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Detecting a change in sound duration is important in language processing. The cerebral reactivity to a duration deviant in oddball paradigm has been reflected as a mismatch negativity (MMN). This study aimed to see cerebral responses to several duration-varying sounds presented with equal probability. Magnetoencephalographic (MEG) and behavior responses to equi-probable sounds (25-50-75-100-125 ms or 50-75-100-125-150 ms tones) were recorded in 10 healthy adult volunteers. By subtracting the average of the responses to 4 longer tones from the response to the shortest tone, a clear deflection peaking at 100-200 ms from stimulus onset was identified. This activity was called as sub-standard MMNm, and its amplitude tended to increase with the increment of duration deviance within a stimulation paradigm. The source of sub-standard MMNm was localized in superior temporal area, with 5-6 mm more anterior to the generator of N100m response. Behavioral tests also showed best performance in the recognition of the shortest tone than longer tones. In conclusion, the preferential response to the shortest tone in an equiprobable paradigm suggests an asymmetrical processing in the auditory cortex for duration-varying sounds.

A 48-year-old woman suddenly lost consciousness as a result of a right rostral pontine tegmentum haemorrhage. The patient presented with decerebrate rigidity (DR) and regained full consciousness 5 days after the initial onset. The patient was given gabapentin 1200 mg/day nasogastrically and her DR significantly improved, although other antiepileptic drugs such as phenytoin and carbamazepine were given in larger dosages to decrease muscle hypertonicity. The patients' preserved consciousness and motor-evoked potentials to transcranial magnetic stimulation indicated a derangement of the extrapyramidal tracts with preservation of the pyramidal tracts. This case report discusses the possible mechanisms of action of gabapentin in DR.

Background:Kennedy's disease (KD) is an X-linked recessive polyglutamine disease. Traditionally, it is a lower motor neuron syndrome with additional features such as gynecomastia and tremor. Sensory symptoms are minimal if ever present. We used multimodal evoked potential (EPs) tests to study the distribution of the involvement of the disease.Methods:Visual, brainstem auditory, somatosensory and motor EPs were studied in six KD patients. All of them had typical presentations and had been proved genetically.Results:Abnormal findings were noted as follows: prolonged peak latencies of visual EPs, increased hearing threshold level, inconsistent brainstem auditory EPs, decreased amplitudes of cortical potentials of somatosensory EPs, and increased motor threshold to transcranial magnetic stimulation.Conclusions:Our multimodal EP studies showed that KD involved multiple levels of the nervous system. It implies the widespread effects of the mutant androgen receptors.

Background: Triptan’s efficacy in the treatment of migraine has never been reported in Taiwanese. A high placebo effect was reported in Japanese. The objective of this study was to evaluate the efficacy of intranasal sumatriptan in the acute treatment of migraine in Taiwanese patients. Methods: Fifty-eight patients who had experienced migraine for at least 1 year were randomly assigned to 2 groups, self-administered intranasal sumatriptan 20 mg or placebo to treat a single migraine attack of moderate or severe intensity. Results: A significant difference in headache relief rates between the 2 groups was observed at 30 minutes postdose (46% vs. 21%, p < 0.05). One hour postdose, 61% of sumatriptan recipients experienced headache relief compared with 43% of placebo recipients (p = 0.181). The difference in relief rates between groups diminished over time, mainly due to a high placebo response (54% at 2 hours postdose). Conclusion: Our study suggests that ethnicity might have a role in placebo response, and highlights the importance of a placebo group in acute migraine trials. However, the small sample size in this study should also be taken into consideration. [J Chin Med Assoc 2007;70(2):39–46]

The magnetic equivalent (MMNm) of mismatch negativity may reflect auditory discrimination and sensory memory. To study whether temporal lobe epilepsy (TLE) affects automatic central auditory-change processing, we recorded magnetoencephalographic (MEG) responses to standard and duration-deviant sounds in 12 TLE patients and 12 age-matched controls, and repeated MEG measurement in 8 patients 6-30 months following epilepsy surgery and in 6 controls 3-8 months after their first measurement. We compared the MMNm between patients and controls, and also evaluated intertrial phase coherences as indexed by phase-locking factors (PLF) using wavelet-based analyses. We observed longer MMNm latencies for patients than for controls. Dipole modeling and minimum-current estimates together showed bi-frontotemporal sources for MMNm. The phase locking across trials was dominant at the 4- to 14-Hz band, and the main difference in PLF between deviant- and standard-evoked responses occurred in the time frame of 150-250 ms after stimulus onset. Notably, in the 5 patients who became seizure free after removal of right temporal epileptic focus, the phase-locking phenomena resulting from deviant stimuli were enhanced, and even more distributed in the frontotemporal regions. We conclude that mesial TLE might affect auditory-change detection, and a successful surgery causes a possible plastic change in phase locking of deviant-evoked signals.

Objective:To determine the impact of check size and interstimulus interval (ISI) on neuromagnetic visual cortical responses.Methods:We recorded visual evoked fields to pattern-reversal stimulation with central occlusion in ten subjects. The ~100 ms magnetic activation (P100m) was analyzed by single dipole modeling.Results:With 1 s ISI, P100m strengths increased as check size increased from 15' up to 120' of visual arc, and larger checks elicited less P100m activation. With 120' checks, we found no P100m attenuation as ISI decreased from 4 s to 0.16 s. P100m sources around the calcarine sulcus did not vary with check size or ISI.Conclusions:The magnitude of cortical activation during visual contrast processing is check size-dependent and the 120' checks are optimum for future studies on neuromagnetic visual cortical functions using central-occluded stimulation. The corresponding neuronal activation demonstrated a short refractory period less than 0.16 s. We also found significantly overlapping cortical representation areas for different check sizes or ISIs.

Myelin protein zero gene (MPZ) mutations may account for a small proportion of cases of Charcot-Marie-Tooth disease (CMT). Different MPZ mutations may be associated with different clinical and electrophysiological phenotypes. To expand our understanding of the characteristics of nerve conduction velocity (NCV) in patients with different MPZ mutations, the authors collected and analysed the NCV values from patients with MPZ mutations. The NCVs of fourteen patients from six families carrying MPZ mutations of Val58Asp, Ser63Phe, Thr65Ile,Arg98Cys, Arg98His, and Ser233fs were collected retrospectively. Five of them had received nerve conduction studies (NCS) twice. The mutations were verified by polymerase chain reaction (PCR) amplifications and nucleotide sequencing. Scatterplot analyses of median motor NCV (MNCV) versus specific MPZ mutation were performed. The median MNCV varied widely, with a mean of 16.3 m/s (SD=7.7 m/s) and a range of 5.1–32.9 m/s. Median MNCVs of patients with particular MPZ mutations were similar. Moreover, Median MNCV did not change significantly over time. There was concordance between median MNCV and specific MPZ mutations. However, median MNCV is not an ideal measure with which to distinguish CMT1B patients with MPZ mutations from CMT1A patients with PMP22 mutations.

Transcranial magnetic stimulation (TMS) of the motor cortex can interrupt voluntary contralateral rhythmic limb movements. Using the method of “resetting index” (RI), our study investigated the TMS effect on different types of bimanual movements. Six normal subjects participated. For unimanual movement, each subject tapped either the right or left index finger at a comfortable rate. For bimanual movement, index fingers of both hands tapped in the same (in-phase) direction or in the opposite (antiphase) direction. TMS was applied to each hemisphere separately at various intensities from 0.5 to 1.5 times motor threshold (MT). TMS interruption of rhythm was quantified by RI. For the unimanual movements, TMS disrupted both contralateral and ipsilateral rhythmic hand movements, although the effect was much less in the ipsilateral hand. For the bimanual in-phase task, TMS could simultaneously reset the rhythmic movements of both hands, but the effect on the contralateral hand was less and the effect on the ipsilateral hand was more compared with the unimanual tasks. Similar effects were seen from right and left hemisphere stimulation. TMS had little effect on the bimanual antiphase task. The equal effect of right and left hemisphere stimulation indicates that neither motor cortex is dominant for simple bimanual in-phase movement. The smaller influence of contralateral stimulation and the greater effect of ipsilateral stimulation during bimanual in-phase movement compared with unimanual movement suggest hemispheric coupling. The antiphase movements were resistant to TMS disruption, and this suggests that control of rhythm differs in the 2 tasks. TMS produced a transient asynchrony of movements on the 2 sides, indicating that both motor cortices might be downstream of the clocking command or that the clocking is a consequence of the 2 hemispheres communicating equally with each other.

Pyruvoyl-tetrahydropterin synthase (6PTPS) deficiency is a major cause of biopterin deficiency. 6PTPS patients usually have an elevated serum phenylalanine level, a deficiency of neurotransmitters (serotonin and dopamine), and neurological symptoms, if without treatment. We herein investigated the possibility of neurological dysfunction in early-treated patients. In the study, 12 early-treated 6PTPS patients were studied. Their auditory simple reaction time, movement rhythm variation (MRV), somatosensory evoked potentials to median nerve stimulation, and hand muscle responses to transcranial magnetic stimulation, were measured. MRV is a test of repetitive voluntary movements, and was used with and without auditory cues at 0.3 Hz. The 6PTPS patients had an increased motor threshold but normal motor and sensory central conduction times. They performed very well in simple reactions (6PTPS 208.4 ^ 16.7 ms, control 200.3 ^ 11.7 ms, p ¼ 0.18), but not in continuous tasks. The continuous performance tests showed that MRV had increased in the 6PTPS patients (with cues: 6PTPS 7.35 ^ 0.94, control 5.47 ^ 0.80, p , 0.0001; without cues: 6PTPS 9.87 ^ 1.44, control 6.59 ^ 0.68, p , 0.0001). Without cues, MRV had increased in both the 6PTPS and control groups, but more significantly in the 6PTPS patients (6PTPS 2.51 ^ 0.97, control 1.25 ^ 0.42; p ¼ 0.0001). Our findings indicate that early-treated 6PTPS patients have subtle neurological dysfunctions. They may not maintain movement rhythm as well as normal subjects, even with external cues. Hence, MRV is a good method to assess motor control. q 2003 Elsevier B.V. All rights reserved.

To compare magnetoencephalography (MEG) with scalp electroencephalography (EEG) in the detection of interictal spikes in temporal lobe epilepsy (TLE), we simultaneously recorded MEG and scalp EEG with a whole-scalp neuromagnetometer in 46 TLE patients. We visually searched interictal spikes on MEG and EEG channels and classified them into three types according to their presentation on MEG alone (M-spikes), EEG alone (E-spikes), or concomitantly on both modalities (M/E-spikes). The M-spikes and M/E-spikes were localized with MEG equivalent current dipole modeling. We analyzed the relative contribution of MEG and EEG in the overall yield of spike detection and also compared M-spikes with M/E-spikes in terms of dipole locations and strengths. During the 30- to 40-min MEG recordings, interictal spikes were obtained in 36 (78.3%) of the 46 patients. Among the 36 patients, most spikes were M/E-spikes (68.3%), some were M-spikes (22.1%), and some were E-spikes (9.7%). In comparison with EEG, MEG gave better spike yield in patients with lateral TLE. Sources of M/E- and M-spikes were situated in the same anatomical regions, whereas the average dipole strength was larger for M/E- than M-spikes. In conclusion, some interictal spikes appeared selectively on either MEG or EEG channels in TLE patients although more spikes were simultaneously identified on both modalities. Thus, simultaneous MEG and EEG recordings help to enhance spike detection. Identification of M-spikes would offer important localization of irritative foci, especially in patients with lateral TLE.

Objectives - We can assess brain function by measuring the cortical relay time (CRT) of long latency reflex (LLR) of hand muscle. We would study if measurement of CRT of LLR can explore the brain involvement of adrenomyeloneuropathy (AMN). Methods - Two AMN patients were included in the study. Both of them had spastic gait and mild sensory deficits but normal mental function. The LLRs were provoked at the first dorsal interosseous muscle by electrical stimulation of the middle finger. We measured the latency of LLR and its CRT. Results - Delayed LLR and prolonged CRT were noted in AMN patients, even though the magnetic resonance imaging of brain did not show any significant abnormalities. Conclusions - Measuring CRT of LLR reveals brain involvement of AMN patients, and it is an adjunct in the assessment of brain function though without specific anatomic diagnosis.

Objectives : Magnetic stimulation of the motor cortex can be used to determine the involvement of the cortex in rhythmic movement disorders. Symptomatic palatal tremor (SPT) is thought to come from a pacemaker that is relatively resistant to internal and external stimulation. In this study, we investigated the effect of magnetic stimulation of motor cortex on SPT. Methods : Five male patients, aged 67–79 years, with SPT after brain stem infarction or hemorrhage, all had a synchronous mouth angle twitch with the palatal movement. Electromyographic activity was recorded with a monopolar needle electrode from orbicularis oris. In experiment 1, transcranial magnetic stimulation (TMS) was delivered at 200% motor threshold (MT) to reset SPT. In experiment 2, the effect of TMS intensities was studied at 80–240% MT in two SPT patients. To determine the influence of the TMS, we used the resetting index (RI). Results : TMS reset the tremor in all 5 SPT patients at 200% MT with RIs of 0.86–0.96. The latency of the tremor reappearance after TMS was longer than the pre-stimulus tremor interval, and the intervals between the subsequent tremor bursts were also prolonged. The degree of tremor resetting was closely correlated with the magnetic stimulus intensity and the latency of the tremor reappearance after TMS. Conclusions : Stimulation of the motor cortex may modulate the generator of SPT.

"Noxious stimulation over the foot can evoke a nociceptive flexor reflex (NR) in the lower limb especially for tibialis anterior muscle (TA). Components of NR include the monosynaptic fast latency NRII, and the polysynaptic slow latency NRIII, supposedly a spinal segmental reflex influenced by the supraspinal control. Pain perception is quantified by visual analogous scale (VAS) and has been reported to be related to NRIII. Previous papers have reported the long lasting effect of transcranial magnetic stimulation (TMS), as well as TMS suppressing pain perception. The purpose of this study was to investigate the immediate and prolonged effect of a single-pulse TMS to suppress NR and pain. NRIII was provoked at right TA by a train of electrical stimulation on the right toe in 10 healthy subjects. TMS was delivered over the vertex area to evoke right anterior tibialis muscle activity. A sham TMS from different directions of the coil was performed on the next day. The NRIII amplitude and VAS were measured. As a result, the amplitude of NRIII was significantly decreased than the control 50 ms pre-stimulation (0.20 ± 0.13 mA vs . 0.65 ± 0.42 mV, P = 0.016), 100 ms pre-stimulation (0.10 ± 0.10 mA vs . 0.65 ± 0.42 mV, P = 0.001), 15 min post-stimulation (0.12 ± 0.09 mA vs . 0.65 ± 0.42 mV, P = 0.004), and 30 min post-stimulation (0.41 ± 0.21 mA vs . 0.65 ± 0.42 mV, P = 0.046). VAS was diminished compared with the control 50 ms pre-stimulation (3.3 ± 0.9 vs . 5.4 ± 1.3, P = 0.002), 100 ms pre-stimulation (2.6 ± 0.5 vs . 5.4 ± 1.3, P0.001) and 15 min post-stimulation (3.5 ± 0.9 vs . 5.4 ± 1.3, P = 0.046). The NRIII amplitude was well correlated with VAS in reduction during the TMS condition and 15 min after electrical stimulation (P0.001). The sham TMS did not suppress NRIII or VAS. In conclusion, our results indicate that NRIII and the nociception can be inhibited by one single pulse TMS and such an effect can last for a period of time."

We investigated cardiovascular autonomic functions in 23 patients with Alzheimer's disease (AD) and 23 age-matched control subjects. The vagal parasympathetic function was assessed with R-R interval variation (RRIV), and sympathetic function with sympathetic skin response (SSR) and orthostatic cardiovascular reflexes. Compared with controls, the AD patients had significantly depressed RRIV during rest (6.4 +/- 1.3% vs. 7.5 +/- 1.6%, p < 0.02) and deep breathing (12.6 +/- 4.6% vs. 17.0 +/- 5.1%, p < 0.006), but all AD patients had normal SSR. After standing for 3 minutes from supine, the changes of blood pressure and heart rate from baseline in AD patients did not differ from those in controls. The AD patients had a lower systolic blood pressure than controls in both supine (130.7 +/- 17.4 vs. 145.4 +/- 20.7 mmHg, p < 0.02) and standing (129.2 +/- 20.1 vs. 146.6 +/- 21.1 mmHg, p < 0.008) positions, especially in those patients with more severe dementia. We conclude that AD patients have mildly impaired autonomic functions, mainly in vagal parasympathetic functions. The pathogenesis and clinical significance of low blood pressure in AD needs further study.

Objectives. Sacral root stimulation (SRS) is a technique to restore the idiopathic overactive bladder (IOB). However, its mechanism of action is yet to be elucidated. Hence, we studied whether SRS restored IOB through the mechanism of spinal neuromodulation. Materials and Methods. Six IOB patients and 10 healthy volunteers were included in the study. The spinal nociceptive reflex was used as the index of spinal excitability and was evoked by electrical stimulation at the foot, with recording at the ipsilateral tibialis anterior. Results. IOB patients had increased spinal excitability to somatic nociceptive stimuli of the lower limbs. This spinal excitability decreased and bladder function improved after SRS, an effect that outlasted actual stimulation by at least 30 min. Conclusions. Our results showed that spinal excitability was increased in response to somatic nociceptive afferents in IOB patients. SRS restored bladder function, at least, in part, through spinal neuromodulation.

The Treatment Guideline Subcommittee of the Taiwan Headache Society evaluated both the acute and the preventive treatments for cluster headache now being used in Taiwan, based on the principles of evidence- based medicine. We assessed the quality of clinical trials and levels of evidence, and referred to other treatment guidelines proposed by other countries. Throughout several panel discussions, we merged opinions from the subcommittee members and proposed a consensus on the major roles, recommended levels, clinical efficacy, adverse events and cautions of clinical practice regarding acute and preventive treatments of cluster headache. The majority of Taiwanese patients have episodic cluster headaches, because chronic clusters are very rare. Cluster headache is characterized by severe and excruciating pain which develops within a short time and is associated with ipsilateral autonomic symptoms. Therefore, emergency treatment for a cluster headache attack is extremely important. Within the group of acute medications currently available in Taiwan, the subcommittee determined that high-flow oxygen inhalation has the best evidence of effectiveness, followed by intranasal triptans. Both are recommended as first-line medical treatments for acute attacks. Oral triptans were determined to be second-line medications. For transitional prophylaxis, oral corticosteroids are recommended as the first-line medication, and ergotamine as the second-line choice. As for maintenance prophylaxis, verapamil has the best evidence and is recommended as the first-line medication. Lithium, melatonin, valproic acid, topiramate and gabapentin are suggested as the second-line preventive medications. Surgical interventions, including occipital nerve stimulation, deep brain stimulation, radiofrequency block of the sphenopalatine ganglion, percutaneous radiofrequency rhizotomy and trigeminal nerve section, are invasive and their long-term efficacy and adverse events are still not clear in Taiwanese patients; therefore, they are not recommended currently by the subcommittee. The transitional and maintenance prophylactic medications can be used together to attain treatment efficacy. Once the maintenance prophylaxis achieves efficacy, the transitional prophylactic medications can be tapered gradually. We suggest the corticosteroids be used within two weeks, if possible. The duration of maintenance treatment depends on the individual patient's clinical condition, and the medications can be tapered off when the cluster period is over.

The sympathetic skin response (SSR) was measured in 35 normal healthy adults and in 40 patients with diabetic polyneuropathy. When recording from the hand or the foot, the SSR latency was the same whether stimulating at the hand or the foot. This may suggest that the conduction velocity of afferent fibers is much faster than that of efferent fibers, so that the former do not contribute to the SSR latency. The SSR amplitudes were significantly reduced in diabetic patients (p < 0.001), but their latencies were normal as long as responses could be detected. It is possible that some surviving unmyelinated fibers and/or regenerated fibers take the responsibility for normal conduction. Another possible explanation is that the postganglionic unmyelinated fibers in polyneuropathy may represent themselves as 'all or none', i.e., either the fibers conduct with normal velocity or they do not conduct at all.

From July 1988 to June 1989, the etiology was registered of 520 patients with generalized neuropathy in 5 neurological centers in Taiwan. The neuropathy was diabetic in 256 cases (49.23%), alcoholic in 45 (8.65%), inflammatory in 34 (6.53%; including 21 with acute inflammatory demyelinating polyneuropathy, 12 with chronic inflammatory demyelinating polyneuropathy, and 1 with chronic relapsing polyneuropathy), 12 with associated malignancy (2.31%), 9 with dysproteinemia (1.73%), uremic in 22 (4.23%), hereditary motor and sensory in 22 (4.23%), toxic in 14 (2.69%), ischemic in 12 (2.31%), hypothyroidism in 10 (1.92%), nutritional deficiency and malabsorption in 6 (1.15%), chronic liver disease in 4 (0.77%), other diseases in 11 (2.12%) and unclassified in 63 (12.12%). This survey provided a crude etiological picture of generalized neuropathy on this island.

We investigated autonomic function in patients with idiopathic Parkinson's disease (PD) by measuring sympathetic skin response (SSR) and R-R interval variation (RRIV). Sixty-two PD patients and 62 age-matched normal subjects were recruited. Abnormal SSR was noted in nine (14.5%) PD patients, including three in Stage II, three in Stage III, and three in Stage IV, but not in Stage I patients or normal subjects. Four of these nine patients had postural hypotension. Abnormal SSR was correlated with duration of illness and impotence. In PD patients, abnormal SSR may be due to intermediolateral column dysfunction. After logarithmic transformation and age adjustment, 19 (31.6%) of 60 PD patients had abnormal RRIV during rest and deep breathing. Abnormal RRIV was not related to staging or duration of illness. Patients with constipation had significantly lower RRIV, indicating parasympathetic dysfunction. RRIV was not affected by acute or chronic L-dopa treatment. The agreement between RRIV and SSR in PD patients was poor (kappa = -0.07). It appears that abnormal SSR, but not RRIV, may be associated with more autonomic disturbances in PD patients.

The Treatment Guideline Subcommittee of the Taiwan Headache Society evaluated the indication of neuroimaging for nonacute headache according to the principles of evidence-based medicine. We have assessed the qualities of studies, levels of evidence, and referred to other guidelines proposed by Western countries. After several panel discussions, we merged opinions from the subcommittee members and proposed a Taiwan consensus. Neuroimaging is not necessary for patients with nonacute and recurrent migraine or tension-type headache when there is no recent change of headache characteristics and neurological examinations are normal. Neuroimaging is suggested for patients who have headaches with abnormal neurological examinations. For patients who are diagnosed as having cluster headache and have never received neuroimaging studies, or patients whose headache characteristics are atypical for cluster headaches, neuroimaging studies should be considered. Neuroimaging is also recommended for patients with cough headache, exertional headache and headache associated with sexual activity. Although the resolution of MRI is superior to CT, evidence is insufficient to make recommendation regarding the choice of MRI or CT for the evaluation of nonacute headache patient. Clinicians should make a judgment by themselves according to the patient's specific conditions.

[No abstract available]

Objective: Differences in physical features and occurrence probability between standards and deviants in oddball paradigms provide contributions to magnetic mismatch negativity (MMNm). We aimed to reduce these influential factors and extract memory-based MMNm by adding a control paradigm. Methods: Magnetoencephalographic responses were recorded in 13 healthy adults with an oddball paradigm (125-ms standard and 50-ms deviant tones) and an equiprobable control paradigm (50-ms control and four other duration-varying tones). The stimulus onset asynchrony was 500 ms. Controlled MMNm was obtained by subtracting control-evoked responses from deviant-evoked responses. Results: With respect to the onset of stimulus difference, the peak latency of controlled MMNm was compatible with previous intracranial MMN recordings. Both controlled and traditional MMNm were generated around the superior temporal cortex, whereas the controlled MMNm amplitude was about 70% of traditional MMNm amplitude. Right-hemispheric dominance was observed in traditional MMNm but not in controlled MMNm. N100m amplitude was smaller in standard-evoked than in deviant- or control-evoked responses. Conclusions: Controlled MMNm reflects memory-based processing of duration changes, whereas traditional MMNm additionally involves non-memory activations related to differential refractoriness states and physical properties between standard and deviant stimuli. Significance: The memory-based processing of auditory deviants may be preferentially extracted by adding a control paradigm.

Objective:This study is aimed to explore the frequency characteristics of pain-evoked neuromagnetic responses in the secondary somatosensory (SII) cortices.Methods:Thulium-laser nociceptive stimuli to the left hand dorsum of 10 right-handed healthy adults. The pain stimuli were rated as mild, moderate, and severe levels according to subjects' reports on a 10-point visual analog scale. We analyzed their cortical responses with wavelet-based frequency analyses and equivalent current dipole (ECD) modeling.Results:For each pain level, we found an increase of theta (4-8 Hz) and alpha (8-13 Hz) power in bilateral SII areas at 180-210 ms after stimulus onset. The power was larger for the moderate than for the mild pain level (p < 0.05), but there was no statistical power difference of these oscillations between moderate and severe pain stimulus conditions (p = 0.7). Within the SII area, we did not observe particular difference in theta and alpha ECD locations between varying pain level conditions.Conclusions:The 4-13 Hz activities, peaking from 180 to 210 ms, are oscillatory correlates of SII activation in response to nociceptive stimulation, but their power may code the magnitude of pain stimuli only up to moderate level, as rated subjectively. This measure could be potentially used to evaluate SII activation in further pain studies.

We consecutively recruited 21 patients (all women, mean 54 ± 8 years) with bath-related thunderclap headache (BRTH). Thirteen of them were in menopause, two had just ceased hormonal therapy, and one was at 3 months postpartum. Bathing was the initial trigger for thunderclap headaches in nine patients (43%). Many patients ( n = 15, 71%) had other non-bath-related attacks. Most patients ( n = 18, 86%) reported that the headache occurred immediately when water was sprayed over their body, with warm water (52%) as the most common. During the disease course [mean 14 days (6-34)], the mean number of BRTH was 5.1 ± 3.6 attacks. Nineteen patients (90%) changed bathing habits to prevent attacks. Thirteen patients (62%) had magnetic resonance angiography vasoconstrictions, and two of them (15%) developed reversible posterior encephalopathy. None of the patients without vasoconstrictions had this complication. Nimodipine was effective in stopping further attacks in 84% (16/19) treated patients. No relapse was reported at a mean follow-up of 30 months. BRTH occurred exclusively in women and predominantly in middle age. Deficiency or fluctuation of female sex hormones may play a role. About 60% patients showed cerebral vasospasms, fulfilling the diagnosis of reversible cerebral vasoconstriction syndrome and indicating a risk of posterior encephalopathy.

Studies suggest that smaller hippocampal volume predicts Alzheimer's disease (AD) in mild cognitive impairment (MCI). However, few studies have demonstrated decline rates in cognition and hippocampal volume in MCI subjects with stable clinical presentation. Furthermore, the effects of apolipoprotein E (ApoE) on the change rates of medial temporal structures and cognition in MCI are rarely investigated. Fifty-eight subjects with amnestic MCI and 20 normal aging elderly controls received annual neuropsychological and magnetic resonance imaging (MRI) assessments. Annual decline rates in neuropsychological test scores, hippocampal and amygdalar volumes were calculated. ApoE genotypes were examined. Nineteen (32.7%) MCI subjects converted to AD during an average 22.5-month follow-up period. The annual hippocampal atrophy rate was correlated with a decline in memory test scores. The presence of the ApoE ɛ4 allele did not affect the change rates in neuropsychological test scores and medial temporal structures volume. Compared to subjects with stable MCI (MCI-S) and normal aging, progressive MCI (MCI-P) had the highest annual decline rates in cognition and hippocampal volume. Logistic regression analysis showed that higher annual decline rates in hippocampal volume and global cognitive test scores were associated with conversion to AD. Furthermore, although MCI-S subjects had little cognitive decline, their hippocampal atrophy rates were higher than those of normal aging controls. Therefore, accelerated hippocampal atrophy rates may be an early and important presentation in MCI subjects.

To evaluate whether the side of stimulated ear affects the hemispheric asymmetry of auditory evoked cortical activations.Using a whole-head neuromagnetometer, we recorded neuromagnetic approximately 100 ms responses (N100m) in 21 healthy right-handers to 100 ms 1 kHz tones delivered alternatively to left and right ear.Although the peak latencies of N100m were shorter in contralateral than in ipsilateral hemisphere, the difference was significant only for the left ear stimulation. Based on the relative N100m amplitudes across hemispheres, the laterality evaluation showed a rightward predominance of N100m activation to tone stimuli, but the lateralization toward the right hemisphere was more apparent by the left than by the right ear stimulation (laterality index: -0.27 versus -0.10, p=0.008). Within the right hemisphere, the N100m was 2-4 mm more posterior for left ear than for right ear stimulation.The hemispheric asymmetry in auditory processing depends on the side of the stimulated ear. The more anterior localization of right N100m responses to ipsilateral than to contralateral ear stimulation suggests that there might be differential neuronal populations in the right hemisphere for processing spatially different auditory inputs.

Nitrous oxide (N2O) damages the nervous system of chronic abusers. Multimodal evoked potentials (EPs) can help document the electrophysiological abnormalities of N2O abusers and its distribution in the nervous system.A 41-year-old male N2O abuser had used N2O (4-5 cans/per day, about 2000 ml/can) for more than 10 years. He complained of progressive motor clumsiness and distal paresthesia in the four limbs. Abnormal laboratory tests were megaloblastic red blood cells (102.3 fL, normal 80-94 fL) and serum vitamin B12 concentration of 143 pg/nL (normal 160-970 pg/nL). An MR image did not show significant findings in the brain but demonstrated conspicuous changes in the posterior and lateral columns at the C2-C7 level, in accordance with the anatomical lesions of the subacute combined degeneration of the spinal cord. In addition to sensori-motor axonal polyneuropathy, multimodal EPs showed abnormal visual EPs with prolonged peak latencies of P100, abnormal brainstem auditory EPs characterized by delayed wave V and difficulty in the recognition of waves I and III, abnormal somatosensory EPs with significant decreased peak amplitudes of cortical potentials bilaterally, and abnormal motor EPs to transcranial magnetic stimulation with prolonged central motor conduction time.Our studies document electrophysiological abnormalities that may be attributed to N2O and indicate that N2O may indirectly involve multiple levels of the nervous system.

Electrical stimulation may produce excitation or inhibition of the motor neurons, as represented the blink reflex and masseter silent period in response to trigeminal nerve stimulation. Clinically, a light touch on the palm may evoke a mentalis muscle response (MMR), i.e. a palmomental reflex. In this study, we attempted to characterize the MMR to median nerve stimulation. Electrical stimulation was applied at the median nerve with recordings at the mentalis muscles. An inhibition study was done with continuous stimuli during muscle contraction (I1 and I2 of MMRaverage). Excitation was done with a single shot during muscle relaxation (MMRsingle) or by continuous stimuli during muscle contraction (E1 and E2 of MMRaverage). The characteristic differences between MMRaverage and MMRsingle were as follows: earlier onset latencies of MMRaverage (MMRaverage45 ms; MMRsingle60 ms), and a lower amplitude of MMRaverage (MMRaverage50 microV; MMRsingle150 microV). The receptive field of MMRsingle was widespread over the body surface and that of MMRaverage was limited to the trigeminal, median and index digital nerves. Series of stimuli usually significantly decreased the amplitude of MMRsingle, as a phenomenon of habituation. On the other hand, it was difficult to evoke the earlier response (i.e. MMRaverage) without continuous stimuli and an average technique. MMRaverage had the components of both excitation (E) and inhibition (I); for example, E1-I1-E2-I2 or I1-E2-I2. E2 was the most consistent component. In patients with dorsal column dysfunction, median nerve stimulation could successfully elicit MMRsingle, but not MMRaverage. Contrarily, in patients with pain sensory loss, it was more difficult to reproduce MMRsingle than MMRaverage. It seemed that MMRaverage and MMRsingle did not have equivalents across the different modalities of stimulation.

Two male patients were diagnosed with adrenomyeloneuropathy. Their chief problems were progressive spastic paraparesis, sensory impairment, hyperpigmentation and testis atrophy. Transcranial magnetic stimulation (TMS) does not easily elicit motor-evoked potentials (MEPs) in patients with a central nervous system dysfunction, even though a few methods, such as contraction of the target muscles and the Jendrassik maneuver (JM), are used in the attempt to facilitate them. In these two patients, we used a conditioning method (prior electrical stimulation over the cutaneous nerve of the left index finger) in order to facilitate MEPs, elicited by TMS, in the left tibialis anterior muscle. In patient 1, facilitation of MEPs was present at conditioning-test (C-T) intervals in the range 60-220 ms, with the maximal MEP recorded at C-T 160 ms; in patient 2, it occurred in the C-T interval range 110-140 ms, with the maximal MEP recorded at C-T 130 ms. By means of conditioning electrical stimulation, we can facilitate MEPs elicited by TMS in those subjects in whom MEPs are minimal or difficult to elicit even using the conventional JM or muscle contraction. The facilitation of MEPs by conditioning stimuli allowed us not only to assess central motor conduction time, but also to demonstrate the preserved continuity of the corticospinal tract in these two patients.

Mitochondrial diseases are heterogeneous disorders affecting multiple systems. Here, we presented the findings of multimodal evoked potential (EP) studies of three siblings with a specific A8344G mutation of mitochondrial DNA. One of them had DM and another two had a history of encephalopathy. Visual EPs were abnormal in one patient and motor, somatosensory and brainstem auditory EPs were observed in all three patients. Our EP studies showed that the A8344G mutation of mitochondrial DNA involved multiple levels of the central nervous system even though there were no correlated symptoms. Therefore EP is an adjunct of methods to detect the functional disturbance and to screen the distribution of the involvement of the nervous system in mitochondrial diseases.

Purposes To elucidate the oscillatory dynamics with respect to interictal spike occurrence in benign rolandic epilepsy (BRE). Methods Using a whole-scalp magnetoencephalography (MEG), we recorded scalp EEG and MEG signals in 10 BRE patients (age 8–12 years) and visually identified unilateral interictal spikes that were simultaneously present on both EEG and MEG channels. We obtained the peak timing of individual spike complex based on MEG single-dipole modeling, and then applied wavelet transform to analyze the time–frequency components of corresponding MEG signals with respect to spike occurrence. Results In the hemisphere with time-domain spike waveforms, we identified a clear increase of 0.5–40Hz activity around the spike peak, most prominent at alpha band (8–13Hz). Notably, at the approximate timing we also observed an increase in 0.5–25Hz oscillations over the homotopic area in the other hemisphere where no spike signals were found. Conclusions Our results indicate bilateral increases in 0.5–25Hz oscillations during unilateral spike formation in BRE patients. By using wavelet transform analysis, one could be able to detect some irritative feature that would in visual analysis remain undetected.

A 68-year-old man developed progressive four-limb weakness and areflexia 17 days after an influenza vaccination. He was diagnosed with Guillain-Barre syndrome (GBS), and remained ventilator dependent and bed-bound for 3 months, despite plasmapheresis and immunoglobulin infusion. However, cognitive impairment, excessive daytime sleepiness, and motor disability were still present, even when he was no longer ventilator dependent. Brain computerized tomography scan and isotope cisternography was consistent with normal pressure hydrocephalus. His motor control and cognitive function recovered almost completely after insertion of a ventriculoperitoneal shunt. Although hydrocephalus is not frequently associated with GBS, our case report indicates that brain imaging is necessary in GBS patients whose cognitive functions deteriorates after disease onset.

To study the neural correlates of Chinese word-appropriateness judgment, we used 2-word phrases and corresponding meaningless pairs produced by replacing the second words (W2) with homophones. Fourteen right-handed healthy adults viewed word pairs randomly presented one word at a time, and judged the lexical appropriateness of the W2 for combining its preceding first word (W1) into a meaningful phrase. We measured magnetoencephalographic (MEG) responses to W1, appropriate W2, and inappropriate W2 stimuli. For each subject, multi-dipole analyses revealed sequential neuromagnetic activations which involved the bilateral visual cortices at approximately 100 milliseconds (ms), the bilateral occipitotemporal regions at approximately 190 ms, and the left temporal lobe at approximately 350 ms (M350) following stimuli. We found that the word appropriateness had no clear effect on the occipitotemporal activation to W2 stimuli, whereas the M350 activation to inappropriate W2 was greater than that to W1 or appropriate W2. In 8 of our subjects, we found an additional activation in the right temporal region, with a smaller amplitude as compared with the left M350. Our results suggest that the M350 activity reflects both lexical and semantic appropriateness assessment. The lateralized M350 strengths may be used to determine the language dominance hemisphere; and additionally, our 2-word contexture judgment paradigm can be applied in further research on the cortical processing of lexicon-semantic information in Chinese speakers.

To study the oscillatory activities during face processing, we recorded magnetoencephalographic responses in 8 healthy subjects to upright and inverted human faces, and obtained the time-frequency representation by using wavelet transform. Delta to beta activities were clearly increased at 140-210 ms after stimulus onset in the bilateral occipitotemporal (OT) areas (t(7)5.5; p0.001), with larger power for theta, alpha and beta over the right side. Notably, more increase alpha activity for inverted than upright face condition was observed in the right OT area. Our results suggest that 4-25 Hz oscillations are involved in face information processing, and the more activation over the right OT implies the right hemisphere advantage for face perception. Moreover, the alpha activity may reflect the differential cortical demands for processing inverted and upright face images.

OBJECTIVE To report a case in which significant hypotension occurred after initiation of tizanidine in a patient using the antihypertensive agent lisinopril. CASE SUMMARY A 48-year-old woman was admitted due to cerebral hemorrhage at the midbrain and pons, with extension to the fourth ventricle. Consciousness disturbance (Glasgow coma scale 4) with a decerebrate posture improved 5 days after stroke onset. As the BP was fairly high, antihypertensive agents, including lisinopril, were initiated. Three weeks later, the decerebrate rigidity and high BP remained, and tizanidine was initiated to see whether the decrease in muscle tone could facilitate hypertension control and motor recovery. However, the BP dropped dramatically within 2 hours after the first dose of tizanidine. The tizanidine and all of the antihypertensive medications were withdrawn. Tizanidine was used again after her BP had stabilized, but did not produce similar problems. DISCUSSION A similar event was reported in 2000. The reaction in our patient appeared after tizanidine initiation and improved after both lisinopril and tizanidine were discontinued. According to the Naranjo probability scale, this was classified as a possible drug interaction. This kind of reaction is seldom mentioned as occurring during co-administration with tizanidine. With its characteristics, tizanidine has the potential to compromise hemodynamic stability during concomitant angiotensin-converting enzyme inhibitor use. CONCLUSIONS Based upon the literature review, the hypotension in this patient was possibly due to the interaction between tizanidine and lisinopril.

By definition, transient ischemic attacks (TIAs) do not leave a neurological deficit beyond 24 hours after onset. However, a subgroup of TIA patients is characterized by persistent perfusion defect on single photon emission computed tomogram or infarction on brain computerized tomogram and magnetic resonance imaging. Here, we applied transcranial magnetic stimulation (TMS) to study whether TIA could produce persistent subclinical dysfunction for more than 24 hours.The study included 23 TIA patients who had the criteria of hand weakness as one of their clinical manifestations. TMS was done twice in each TIA patient. The first time was during the period of 24-48 hours after onset and the second 7 days after onset. We studied the cortical motor threshold, the latencies and the amplitudes of the motor evoked potentials, the central motor conduction time, and the cortical silent period at the intensity of 1.5 times motor threshold with maximal voluntary isometric contraction. The recording was at the first dorsal interosseous muscle.There was no significant difference between the whole group of TIA patients and normal control. However, in the subgroup of TIA patients who had hand weakness more than 1 hour, they had increased motor threshold and prolonged cortical silent period during the first test. Both improved 1 week after onset. On the contrary, in TIA patients who had hand weakness less than 1 hour, their data were all within normal limits during the first and the second studies.Our results indicate that the motor function of TMS study will recover to full if the motor symptoms subside within 1 hour in TIA patients. Subclinical motor deficits may persist in TIA patients who have motor symptoms more than 1 hour.

Hand movement constitutes the most common daily activities in our life. Hand dexterity is often impaired in patients with neurological disease. We developed an adjunct method, based upon the electrodiagnostic software, for study of motor control and hand dexterity.Thirty-two normal subjects, 2 stroke patients and 2 Parkinson patients were included in the study. All of them were right-handed, and were asked to pace rhythmic finger tapping at a comfortable rate without cue or any external stimuli. A trigger kit was designed to transform the finger tapping. After using the triggering mode and adjusting the sweep speed, 2 tapping signals were simultaneously displayed on the screen. The first signal was the triggering potential, and the variation in timing of the second signal represented the variation in timing of the inter-response interval. Twenty sweeps were recorded, superimposed and measured on the screen. Movement rhythm variation (MRV) was defined as b/a x 100 (b = [maximal interval of finger tapping - minimal interval of finger tapping]; a = [maximal interval of finger tapping + minimal interval of finger tapping]/2). Each subject started with right hand and then left hand.MRV measurement showed excellent intrarater (r = 0.97) and interrater (r = 0.97) reliability. In normal right-handed subjects, the MRV was better in right hand than in left hand (right 16.5 +/- 4.1% and left 21.0 +/- 7.6%; p0.05). The MRV improved in stroke patients along with the recovery and improved in Parkinson patients after levodopa treatment.MRV was a good method to provide quantitative data for assessment of hand dexterity. Our study also showed the potential role of MRV in motor control study.

The purpose of this study was to study the relationship between interictal spike sources and somatosensory cortices in benign rolandic epilepsy of childhood (BREC) using a whole-scalp neuromagnetometer. We recorded spontaneous magnetoencephalography (MEG) and EEG signals and cortical somatosensory-evoked magnetic fields (SEFs) to electric stimulation of the median nerve in 9 children with BREC. Interictal rolandic discharges (RDs) and SEFs were analyzed by equivalent current dipole (ECD) modeling. Based on the orientation and locations of corresponding ECDs, we compared generators of RDs with primary (SI) and second somatosensory cortices (SII). Our results showed that RDs and SII responses had similar ECD orientation on the magnetic field maps. The ECDs of RDs were localized 15.3 +/- 1.9 and 12.2 +/- 2.8 mm anterior to SI and SII, respectively. The spatial distance on average from the location of RDs to SII (21.9 +/- 1.6 mm) cortex was significantly shorter than to SI cortex (29.7 +/- 1.7 mm) (P

Background : Charcot–Marie–Tooth disease type 1 (CMT1) is the most common inherited peripheral neuropathy and represents a genetically heterogeneous condition. In addition to the peripheral myelin protein 22 gene ( PMP22 ) duplication (CMT1A), myelin protein zero gene ( MPZ ) mutations may account for a certain portion of CMT1 patients (CMT1B). Objectives : The authors analyzed the MPZ mutations in Taiwanese patients who do not have PMP22 duplication. Specifically, their clinical and molecular features were characterized. Materials and methods : Twenty-four of 57 unrelated Taiwanese patients with CMT1 were selected after excluding the CMT1A duplication. Subsequent analysis of the coding regions of the MPZ gene was performed with single-strand-conformation polymorphism (SSCP), which was then followed by nucleotide sequencing. Results : Four missense mutations and one 4-base pair (bp) deletion, respectively, were identified in five patients, of which one mutation, c.173 T>A, has never been previously reported. Three missense mutations were located in exon 2, the other one in exon 3, and the deletion in exon 6. Conclusions : This study expands the number of CMT1 associated MPZ mutation and suggests that analysis of the coding sequence of MPZ should be performed in all CMT patients without CMT1A duplication to clarify their disease nature.

It has been shown that thrombolytic therapy can improve clinical outcome in some patients with acute cerebral ischemia. These patients have been reported to be characterized by certain clinical and imaging findings, mainly with non-contrast enhanced computed tomography (CT). Our purpose in this study was to find out whether CT angiography (CTA) information about the status of the cerebral vessels is helpful in the selection of patients who may benefit the most from thrombolytic therapy for acvte cerebral ischemia. CTA was prospectively performed in 15 consecutive patients (6 women and 9 men; age range 44-83 years) with moderate or severe symptoms of hyperacute cerebral ischemia. The clinical manifestations of the patient’s condition and the findings on CTA were analyzed. Three-dimensionally reconstructed CTA images of diagnostic quality could be obtained for all 15 patients. Of the 15 patients 14 had a vessel occlusion identified on CTA, which was consistent with and/or helpful for making the clinical diagnosis in all 14 cases; one patient had an aneurysm of the anterior communicating artery without detectable hemorrhage on CTA. Although a thrombolytic agent was not given because of CTA evidence of intracranial aneurysm, the patient nevertheless developed a massive subarachnoid hemorrhage during hospitalization. Ischemic symptoms reversed after CTA and before the initiation of thrombolytic therapy in 2 patients whose CTAs showed occlusion of secondary branch of the middle cerebral artery (MCA). CTA can provide important information before the initiation of thrombolytic therapy. Identification both of the occluded vessel and of an intracranial aneurysm is feasible with the use of CTA, which is particularly important if the intracranial aneurysm is a potential contraindication to thrombolytic therapy. Occlusion of a secondary branch of the MCA and internal carotid artery occlusion are valuable prognostic predictors.

Objective : Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disorder characterized by a slowly progressive ataxia and dysarthria. Anatomically, SCA6 was said to affect only the cerebellum. However, it has been argued that SCA6 may involve widespread regions of the brain. This study was designed to investigate the electrophysiological functions of the central nervous system in patients affected with SCA6. Methods : Nine patients with SCA6 and 10 normal, age-matched control subjects were included in the study. The motor evoked potentials, somatosensory evoked potentials, and long latency reflex (LLR) of the hand muscle were measured to evaluate the functions of the central nervous system. Results : Significantly delayed LLR, as well as prolonged cortical relay time (CRT) and central motor conduction time (CMCT) of the hand muscle, were noted in the patients with SCA6. Conclusions : The prolongation of CMCT and CRT suggested that SCA6 disturbed the functions of the corticospinal tract and the transcortical polysynaptic pathways from the sensory to motor cortices. It seems likely that the CNS dysfunction caused by SCA6 is not limited to the structures that are anatomically abnormal. Furthermore, the prolongation of CMCT alone does not seem to suffice to differentiate between various types of autosomal dominant cerebellar ataxias. Molecular analysis is indispensable for the diagnosis of different genetic types of SCA.