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ObjectiveTo describe the clinical, genetic, and disability profile of pediatric distal hereditary motor neuropathy (dHMN) and to determine the utility of an outcome measure validated for children with Charcot-Marie-Tooth disease (CMT) in assessing disability in this cohort.MethodsWe reviewed the clinical, neurophysiologic, and disability data on individuals with dHMN, evaluated before the age of 20 years, at 2 tertiary neuromuscular clinics in Australia and Spain. Disability was assessed annually with the CMT Pediatric Scale (CMTPedS) in a subset of individuals.ResultsTwenty-two children (13 female) from 19 families were included. Fourteen individuals were symptomatic in the first year of life. Intellectual disability was present in 6 individuals; upper motor neuron signs were seen in 8. Pathogenic variants were found in 9 families, more frequently inBICD2(BICD2-4,DYNC1H1-2,MFN2-2,GARS-1). A novel pathogenic variant in theGARSgene was detected and characterized phenotypically. Disability was moderate on the CMTPedS (mean [SD] 18.2 [6.3], n = 16), with balance and long jump being the most affected and sensation items and grip strength the least affected. Over 1 year, the CMTPedS total score deteriorated, on average 1.5 points (SD 3.7) or 9% (n = 12), with significant variability in the rate of progression within the cohort.ConclusionsThe genetic profile of pediatric dHMN is different from that identified in adult cohorts. This study has identified distinct functional limitations for the CMTPedS in children and adolescents with dHMN.

A 57-year-old woman presented with progressive ataxia and falls. She was in her usual state of health until she developed sudden onset of progressive imbalance for a month. She then presented to an emergency department. Examination revealed significant vibration sensation impairment and proprioceptive loss, with normal pinprick and temperature sensation; sensory ataxia with pseudoathetosis in the hands; no finger to nose incoordination; normal rapid alternating movements of upper extremities; heel to shin incoordination; diminished deep tendon reflexes; wide-based gait; and positive Romberg test. She did not have cognitive impairment, nystagmus, dysarthria, weakness, muscle atrophy, or fasciculations.

We describe a 21-year-old woman with lower extremity spasticity, dystonia, and weakness. She was born full term without complications. At 5 years of age, she began dragging her right foot, which slowly progressed to bilateral toe walking and a wide-based stance. By 14 years of age, she walked with her legs in a fixed posture with knees extended, and by 21 years of age, she was unable to stand unassisted. Family reported an intermittent hand action tremor and large “jerks” of her legs in the evening. They also noticed intermittent slurred speech that was difficult to understand. She reported occasional tingling in her fingers and toes. She completed the 5th grade, but schooling was eventually stopped because of learning difficulties. There is no family history of similar problems or consanguinity. Neurologic examination showed scanning and slurred speech, decreased strength and spasticity in the lower extremities, and a mild, low-amplitude, high-frequency terminal action tremor of both hands. Reflexes were increased at the knees (grade 3) with upgoing plantar responses, and there was decreased vibration and proprioception sensation at the toes. Upon standing, she had dystonic posturing of bilateral lower extremities.

A 68-year-old Vietnamese man presented to the hospital with rapid cognitive decline. One week after returning from a trip to Vietnam, he developed progressive confusion, day–night reversal, memory loss, and slowed speech and gait. No preceding febrile illness was reported. After 2 weeks of symptoms, he was admitted to a hospital and treated with steroids and IV immunoglobulin therapy due to concern for autoimmune encephalitis (AE). Soon thereafter, he was transferred to our facility due to lack of clinical improvement and extension of T2 hyperintense signal on repeat MRI, detailed below. On examination, the patient was alert, with marked abulia and impaired orientation, attention, naming, and following commands. He had frontal release signs including glabellar, grasp, and snout reflexes. His cranial nerve examination including funduscopic examination was unremarkable. There was mildly increased tone in his bilateral arms but not his legs with normal strength throughout. His left arm was hyperreflexic in the brachioradialis and biceps without additional pathologic reflexes, including Hoffman or Babinski signs, or additional lateralization. His sensation and coordination were unremarkable.

A 40-year-old woman presented to the neuromuscular clinic for evaluation of chronic right shoulder weakness of 1-year duration. During that time, she noticed progressive difficulties lifting her right arm overhead and reaching for objects on the back seat of her car. Around 3 months after the onset of shoulder weakness, she started to develop an intermittent achy sensation behind the right ear and hoarseness of her voice. She noted difficulty talking over loud noises and in phone conversations. She denied vision, taste, or hearing changes, dysphagia, dyspnea, numbness, or weakness in other limbs.

A 49-year-old woman with no relevant medical history presented to an external neurology clinic with progressive hand and foot paresthesia and gait instability for over 6 months. Initially, she reported tingling and shooting electrical-type sensations involving her feet. Within several weeks of the onset of paresthesia, she noted a burning pain sensation involving the left hand. Sensory symptoms continued to worsen and she felt pressure-like sensation around the neck and scalp region. This was shortly followed by right hand numbness and loss of dexterity. Over the next month, she developed progressive gait imbalance and transitioned to a cane for ambulation.

ObjectiveWe applied direct cortical stimulation (DCS) to the orbitofrontal cortex (OFC) in neurosurgical patients implanted with intracranial electrodes to probe, with high anatomic precision, the causal link between the OFC and human subjective experience.MethodsWe administered 272 instances of DCS at 172 OFC sites in 22 patients with intractable focal epilepsy (from 2011 to 2017), none of whom had seizures originating from the OFC.ResultsOur observations revealed a rich variety of affective, olfactory, gustatory, and somatosensory changes in the subjective domain. Elicited experiences were largely neutral or negatively valenced (e.g., aversive smells and tastes, sadness, and anger). Evidence was found for preferential left lateralization of negatively valenced experiences and strong right lateralization of neutral effects. Moreover, most of the elicited effects were observed after stimulation of OFC tissue around the transverse orbital sulcus, and none were seen in the most anterior aspects of the OFC.ConclusionsOur study yielded 3 central findings: first, a dissociation between the “silent” anterior and nonsilent middle/posterior OFC where stimulation clearly elicits changes in subjective experience; second, evidence that the OFC might play a causal role in integrating affect and multimodal sensory experiences; and third, clear evidence for left lateralization of negatively valenced effects. Our findings provide important information for clinicians treating OFC injury or planning OFC resection and scientists seeking to understand the brain basis for the integration of sensation, cognition, and affect.

Objective:To describe a second hereditary sensory autonomic neuropathy type VI (HSAN-VI) family harboring 2 novel heterozygous mutations in the dystonin (DST) gene and to evaluate their effect on neurons derived from induced pluripotent stem cells (iPSC).Methods:The family consisted of 3 affected siblings from nonconsanguineous healthy parents. All members underwent clinical and electrophysiologic evaluation and genetic analysis. Two patients underwent quantitative sensory testing (QST), cardiovascular reflexes, dynamic sweat test, and skin biopsy to evaluate somatic and autonomic cutaneous innervation and to get fibroblast cultures for developing iPSC-derived neurons.Results:Onset occurred in the first decade, with painless and progressive mutilating distal ulcerations leading to amputation and joint deformity. Sensation to pain, touch, and vibration was reduced. Autonomic disturbances included hypohidrosis, pupillary abnormalities, and gastrointestinal and sexual dysfunction. Nerve conduction studies showed a severe axonal sensory neuropathy. QST and autonomic functional studies were abnormal. Skin biopsy revealed a lack of sensory and autonomic nerve fibers. Genetic analysis revealed 2 pathogenic mutations in the DST gene affecting exclusively the DST neuronal isoform-a2. Neurons derived from iPSC showed absence or very low levels of DST protein and short and dystrophic neuritis or no projections at all.Conclusions:Unlike the previous HSAN-VI family, our description indicates that DST mutations may be associated with a nonlethal and nonsyndromic phenotype. Neuronal loss affects large and small sensory nerve fibers as well as autonomic ones. Induced-PSC findings suggest that dystonin defect might alter proper development of the peripheral nerves. Dystonin-a2 plays a major role in the HSAN-VI phenotype.

Autism spectrum disorders (ASDs) are a group of complex, heterogeneous, and pervasive neurodevelopmental disorders, characterized by diverse manifestations including impairment in social abilities, decreased or disordered verbal communications, and restricted or repetitive behaviors.1 Abnormalities in sensory perception and processing have long been recognized in up to 90% of individuals diagnosed with ASD.2 These observations have been ascribed to alterations in central sensory processing, especially in the multimodal integration of sensory information.3 However, given the pervasiveness of ASD, the possibility of peripheral sensory nervous system (PNSs) dysfunction should be considered as well. Evidence of enteric nervous system as well as auditory changes4,5 has raised this intriguing possibility.

A 38-year-old, right-handed woman presented to the epilepsy clinic for evaluation of recurrent spells. These spells are characterized by an aura of a “rushing” cephalic sensation and a sense of “spaciness” or “dizziness” followed by loss of awareness with subsequent amnesia for the event. During these events, the patient is observed by family to sit down and slump forward or fall, followed by hyperventilation and occasionally staring, for up to 3 minutes. There is no head turn, eye deviation, or abnormal body movements. Postictally, she reports generalized weakness without focality and confusion. The spells occurred sporadically for 8 years, but recently increased in frequency to 5 to 20 times per day. Triggers included lack of sleep, stress, and various food products. The patient reported some improvement with levetiracetam therapy at 1,500 mg twice daily.

A 15-year-old previously healthy boy was referred for further evaluation of wrist pain. Right and left wrist pain started 2 years ago and got significantly worse in the setting of intentional 25-pound weight loss over 6 months. He also had numbness in the 4th and 5th digits of his left hand for the last 3 months. Neurologic examination was notable for weakness of both thumb abduction, finger abduction, and flexion of 4th and 5th digits on the left. There was decreased sensation to pinprick in palms, as well as trace deep tendon reflexes at biceps, triceps, and brachioradialis.

Two unrelated young girls were evaluated for a gait suspected to be functional (video). Hip movements during ambulation were excessive despite normal tone, strength, sensation, and muscle stretch reflexes. Ascertainment of joint hypermobility led to the diagnosis of Ehlers-Danlos syndrome in both. Coxa saltans, also known as “dancer's hip” or “snapping hip,” may develop among young athletes with clicking joints due to connective tissue disorders.1 The gluteus maximum tendon, iliotibial band, or tensor fascia lata slide back and forth across the greater trochanter during flexion–extension movements in external coxa saltans (figure). Case 1 required bilateral iliotibial band lengthening surgery.2

A 52-year-old man presented with sudden onset of acral paresthesia and imbalance. The patient did not have any recent illness, sick contacts, or travel abroad. He denied weakness, pain, bowel or bladder incontinence, dysphagia, dysarthria, or shortness of breath. On neurologic examination, 1 month into his symptoms, he had reduced muscle strength in his finger spread, extension, and flexion on both sides graded on Medical Research Council scale 4−/5 and in toe extensors −4/−4 and toe flexors −4/4. The rest of his muscle strength was normal. Reflexes were absent throughout. He had reduced sensation to all modalities in a length-dependent pattern up to his midshin and wrists on both sides. He was severely unsteady when walking and he could not tandem. Romberg was positive. The rest of his neurologic examination was normal apart from high arches and hammertoes. The patient had a family history of Charcot-Marie-Tooth disease type 1A (CMT1A) ( PMP22 duplication) and was himself tested, although asymptomatic, and was also found to be carrying the mutation.

A 14-year-old boy presented to the University of Rochester Pediatric Movement Disorder clinic for abnormal movements of 1 year’s duration. He was referred to the Movement Disorder clinic for evaluation of complex tics. His movements were stereotyped and often preceded by a blank stare, sometimes associated with a “guttural sound.” He also reported having a “numb” sensation prior to the movements. He denied volitional control of the movements or ability to suppress them. He reported movements only occurring during the day although parents recalled a period of nightly episodes witnessed while sharing a hotel room with him. They occurred both at home and at school. His abnormal movement episodes were about 10–15 seconds in duration and followed by immediate return to normal activities (see video at [Neurology.org][1]). At the time of our evaluation, he was having over 10 episodes a day. [1]: http://neurology.org/lookup/doi/10.1212/WNL.0000000000004339

A 71-year-old woman with juvenile-onset rheumatoid arthritis presented with right trigeminal mandibular pain and dysphonia on a background of 6-month oropharyngeal dysphagia and C3-C5 laminectomy in 2010. She had severe deforming polyarthropathy. Neurologic examination revealed bilateral tongue wasting, loss of tongue protrusion, and right vocal cord paresis. Uvula movement and pharyngeal and facial sensation were normal. MRI (figure, A and B) demonstrated a large cervical synovial pannus extending across the skull base. Multiple cranial neuropathies are extremely rare in rheumatoid arthritis1,2 and should raise suspicion of cervical spine pannus. Aggressive disease-modifying medical therapy may obviate need for neurosurgery.1

A 71-year-old woman presented with a 1-week history of progressive weakness involving her lower extremities, leading to an inability to walk. She also noticed diminished sensation in her lower extremities. She did not complain of bowel or bladder dysfunction. She did not have any neurologic symptoms in her upper extremities. She experienced an upper respiratory tract infection 5 days prior to the start of these symptoms and was treated with antibiotics. There was no history of headache, impaired cognition, or speech impairment.

A 74-year-old man presented with phantom pain secondary to left brachial plexus avulsion (BPA) following a motorcycle accident. He described severe pain (10/10) and presence of a “third arm” with onset 4 weeks after trauma. Neurologic examination showed a left flail arm without sensation.

A 19-year-old man with no significant medical history noted 3 weeks of right facial numbness and slurred speech. On examination, he had decreased sensation in the right middle and lower trigeminal nerve distributions, right tongue deviation, and bilateral facial weakness. A lumbar puncture yielded CSF with a lymphocytic predominant pleocytosis (50 leukocytes/mm3, 95% lymphocytes), elevated protein (260 mg/dL), and normal glucose (49 mg/dL), without other evidence of inflammation or infection, while serum studies were normal. Brain MRI with gadolinium demonstrated a subcentimeter left frontal subcortical white matter lesion on fluid-attenuated inversion recovery images and a nonenhancing pineal cyst.

A 16-year-old left-handed boy with Tourette syndrome (TS) presented to the outpatient neurology clinic complaining of difficulty focusing and completing tasks resulting in impairment at home, school, and social gatherings. He developed recurrent sniffing and throat clearing at age 6, which waxed and waned over time, and had since experienced repeated movements of the head, face, hands, and legs and gulping vocalizations; a diagnosis of TS was established at age 7. His tics were preceded by a premonitory sensation and were partially suppressible. These symptoms led to discomfort, but not impairment. He struggled with planning and organizational skills since age 6, and at age 12 developed repeated washing and writing/rewriting rituals. Family history was notable for a maternal grandmother with attention-deficit/hyperactivity disorder (ADHD) and a father with repetitive eye-blinking and possible childhood obsessive-compulsive disorder (OCD). He had a normal birth followed by normal developmental milestones. Neurologic examination including smooth pursuit and voluntary saccadic eye movements was unremarkable.

Flashes of light or phosphenes are the sensation of light without light actually entering the eye. This phenomenon can be evoked by stimulation of the retina or the visual cortex of the brain and can appear unilaterally or bilaterally. From an ophthalmologic perspective, phosphenes can arise from photoreceptor induction by mechanical,1,2 inflammatory,3 or vascular4 stimuli. Therefore, it is necessary to determine the origin of phosphenes for further management. We encountered a patient who reported having phosphenes while moving his eyes laterally. We performed various ophthalmologic imaging studies to identify the origin of these phosphenes. Acknowledgment: The authors thank Florence Umuhoza, Lise Scandella, and Sarah Exbrayat for technical assistance and the patients for participation in the study.

Aberrant regeneration (AR) of axons may occur following nerve trauma or compression and causes axonal signals to be misdirected to structures other than their original targets. Ocular–oral synkinesis and gustatory hyperlacrimation (crocodile tears), which can each follow facial nerve palsy, are examples of motor and autonomic AR, respectively. Somatosensory AR is rarely reported, and causes the referral of a sensory stimulus at one location to a distant site; the referred sensation is usually perceived as more noxious than the initiating stimulus.1

A 9-year-old previously healthy Filipino-American boy presented to a peripheral hospital with a 2-day history of sudden-onset right arm weakness in the setting of intermittent fevers for 1 week prior to presentation. Over the 2 days prior to presentation, he lost the ability to write, grab any objects, or make a fist with his right hand, as well as the ability to lift his right arm to dress himself. Motor examination of the right arm revealed low tone, 0/5 strength for wrist extension, elbow flexion, and elbow extension, and minimal movement of all right hand interossei and lumbricals. Right trapezius strength was 5/5. Lower extremity strength was 5/5 bilaterally. Sensation to light touch, pinprick, position sense, and vibration was intact in the affected limb. Cranial nerves 2 through 12 were grossly intact. Deep tendon reflexes were absent in the right upper extremity and normal on the left. He denied arm pain, change in sensation, recent trauma, and bladder or bowel dysfunction. The pediatric neurology team was consulted and he was admitted to the pediatric ward at the peripheral hospital for further evaluation.

Objective: To investigate clinical differences in warm and cold complex regional pain syndrome (CRPS) phenotypes. Background: CRPS represents inhomogeneous chronic pain conditions; approximately 70% patients with CRPS have “warm” affected limbs and 30% have “cold” affected limbs. Methods: We examined 50 patients with “cold” and “warm” CRPS (n 25 in each group). Both groups were matched regarding age, sex, affected limb, duration of CRPS, and CRPS I and II to assure comparability. Detailed medical history and neurologic status were assessed. Moreover, quantitative sensory testing (QST) was performed on the affected ipsilateral and clinically unaffected contralateral limbs. Results: Compared with patients who had warm CRPS, patients who had cold CRPS more often reported a history of serious life events (p 0.05) and chronic pain disorders (p 0.05). In cold CRPS, the incidence of CRPS-related dystonia was increased (p 0.05), and cold-induced pain had a higher prevalence (p 0.01). Furthermore, QST revealed a predominant sensory loss in patients with cold CRPS (p 0.05). In contrast, patients with warm CRPS were characterized by mechanical hyperalgesia (p 0.05) in the QST of affected limbs. Conclusion: Our results indicate that warm and cold complex regional pain syndromes (CRPS) are associated with different clinical findings, beyond skin temperature changes. This might have implications for the understanding of CRPS pathophysiology. Neurology ® 2009;72:505–512

Objective: To characterize sensory symptoms in patients with stroke occurring in the cerebral cortex. Methods: We studied clinical and imaging findings of 24 patients who had prominent sensory symptoms without definitive motor dysfunction. Results: According to the sensory manifestations, patients were divided into dominant impairment of primitive sensation (DIPS) group, dominant impairment of cortical sensation (DICS) group, and paresthesia-only group. DIPS was related to lesions involving the parietal operculum and the insular cortex, whereas DICS was related to the lesions affecting the postcentral gyrus. Patients with paresthesia only had smaller lesions located in the postcentral gyrus. DIPS group patients were more often women ( p = 0.013), more often had dysarthria (n = 0.043), and more often developed central poststroke pain or paresthesia (n = 0.005) than the DICS group patients. Restricted sensory changes are common, predominantly involving the perioral or finger areas. Conclusions: Sensory patterns in these patients are generally consistent with the dichotomized (SI and SII) sensory system in the cerebral cortex. Involvement of insular and opercular areas is related to primitive sensory impairment and development of central poststroke pain, whereas postcentral gyrus involvement is related to cortical sensory loss without poststroke pain. The pattern of restricted sensory changes is generally consistent with the Penfield sensory topography.

A hallmark of the later stages of multiple sclerosis (MS) is the gradual decline in walking, which both limits mobility and increases risk of injury from falling. Walking is a complex task, involving strength, coordination, and sensation. Like many complex neurologic functions, walking is easy to observe, but difficult to measure. While early characterization of walking dysfunction in MS focused on maximum walking distance and need for assistive devices (i.e., a cane or walker), more recent metrics target walking speed and distance walked within a period of time (i.e., 3-minute walk).

Objective: Using a single patient case study, we aimed to look at the interaction between full face transplantation and subsequent somatosensory representation in the cortex. Methods: We present a patient with full face transplantation who has recovered primary sensory modalities. The patient also has facial sensations such as touch perception in sensory examinations of the hands and fingers. Results: fMRI findings show interactions between the cortical representations of the face and hand. Conclusion: This phenomenon is one of the well-known referred sensations and reveals how face transplantation relates to cortical plasticity.

Background: In the standard neurologic examination, outcome measures of sensation testing are typically qualitative and subjective. The authors compared the outcome of vibratory sense evaluation using a quantitative Rydel-Seiffer 64 Hz tuning fork with qualitative vibration testing, and two other features of the neurologic evaluation, deep tendon reflexes and sensory nerve conduction studies. Methods: The authors studied 184 subjects, including 126 with Waldenstrom’s macroglobulinemia and 58 controls, over the course of a weekend. Standard neurologic examinations and quantitative vibratory testing were performed. Sensory nerve action potentials (SNAP) were tested as a measure of sensory nerve function. Tests were carried out by different examiners who were blinded to the results of other testing and to clinical information other than the diagnosis of Waldenstrom’s macroglobulinemia. Results: Quantitative vibration measurements in all body regions correlated with sural SNAP amplitudes. Quantitative vibration outcomes were more strongly related to sural SNAP results than qualitative evaluations of vibration. Quantitative vibration testing also detected a loss of sensation with increased age in all body regions tested. Conclusions: Quantitative vibratory evaluation with Rydel-Seiffer tuning fork is rapid, has high inter- and intrarater reliability, and provides measures for evaluating changes in sensory function over time. Examinations with the quantitative tuning fork are also more sensitive and specific than qualitative vibration testing for detecting changes in sensory nerve function. Use of the quantitative tuning fork takes no more time, provides more objective information, and should replace the qualitative vibratory testing method that is now commonly used in the standard neurologic examination.

Flashes of light or phosphenes are the sensation of light without light actually entering the eye. This phenomenon can be evoked by stimulation of the retina or the visual cortex of the brain and can appear unilaterally or bilaterally. From an ophthalmologic perspective, phosphenes can arise from photoreceptor induction by mechanical,1,2 inflammatory,3 or vascular4 stimuli. Therefore, it is necessary to determine the origin of phosphenes for further management. We encountered a patient who reported having phosphenes while moving his eyes laterally. We performed various ophthalmologic imaging studies to identify the origin of these phosphenes.

An 18-year-old man presented with acute weakness of the left limbs, tingling, and reduced light touch sensation at the right side.

A 40-year-old woman with complex partial seizures and right hippocampal atrophy (figure, A and B) had persistent seizures after epilepsy surgery. One of her seizures is shown in the video on the Neurology ® Web site at [Neurology.org][1]. She pushes the event button during the aura (rising epigastric sensation), rubs her mouth, reaches for water, and holds onto it through the seizure. Acknowledgment: The authors acknowledge the help of Ms. Sheila Jackson in obtaining the video and the EEG from the system. [1]: http://neurology.org/lookup/doi/10.1212/WNL.0000000000002662

A 58-year-old woman with hypertension and bilateral carpal tunnel syndrome presented with acute paresthesias in her right hand and foot. She had decreased sensation to vibration and pinprick in a right-sided stocking-glove distribution. MRI of the pons confirmed an acute infarction of a paramedian branch of the basilar artery in the left medial lemniscus (figure). In the posterior column pathway, sensory projections from the face, arm, and leg are somatotopically arranged medially to laterally within the medial lemniscus.1,2 Although strokes classically present with numbness, both thalamic and medial lemniscal infarcts can explain acute hemidysesthesias.

Objective: To determine the effect of dalfampridine (4-aminopyridine), a broad-spectrum, voltage-dependent potassium channel blocker, on patients with trigeminal nerve dysfunction due to multiple sclerosis (MS). Methods: We reviewed histories of 71 patients in our clinic with clinically definite MS who were treated with dalfampridine for at least 2 to 3 months. Of the 71 patients, 5 had a history of either trigeminal neuralgia or altered facial sensation. Results: Of these 5 patients, 3 with preexisting trigeminal neuralgia had a marked worsening of facial pain in close proximity to starting dalfampridine. One patient with altered facial sensation developed trigeminal pain after being on dalfampridine for 18 months. Pain in this individual rapidly subsided when dalfampridine was discontinued. Pain in the worsened 3 patients persisted, became more refractory to previously effective medications, and in one instance required trigeminal surgery for pain control. Conclusions: Dalfampridine should be used with caution in persons with trigeminal neuralgia due to MS. Classification of evidence: This study provides Class IV evidence that treatment with dalfampridine may precipitate or exacerbate preexisting trigeminal neuralgia.

In recent years there has been a paradigm shift in theoretical neuroscience in which the brain—as a passive processor of sensory information—is now considered an active organ of inference, generating predictions and hypotheses about the causes of its sensations. In this commentary, we try to convey the basic ideas behind this perspective, describe their neurophysiologic underpinnings, and highlight the potential importance of this formulation for clinical neuroscience. The formalism it provides—and the implementation of active inference in the brain—may have the potential to reveal aspects of functional neuroanatomy that are compromised in conditions ranging from Parkinson disease to schizophrenia. In particular, many neurologic and neuropsychiatric conditions may be understandable in terms of a failure to modulate the postsynaptic gain of neuronal populations reporting prediction errors during action and perception. From the perspective of the predictive brain, this represents a failure to encode the precision of—or confidence in—sensory information. We propose that the predictive or inferential perspective on brain function offers novel insights into brain diseases.

A 27-year-old crane operator presented with left hand numbness of 3 months' duration. He reported pain above the left elbow following a trivial trauma prior to symptom onset. There was no involvement of other extremities. On examination, there was no wasting of the hand intrinsic muscles but mild weakness of the left abductor digiti quinti with normal power of long hand flexors. Sensation was impaired over the dorsal and volar medial one and half fingers and palm. Deep tendon reflexes were 2+ with normal neurologic examination of the other extremities. There was tenderness and fullness over the left medial elbow. Systemic examination was unremarkable.

Objectives: To investigate the pattern of functional organization in the human visual cortex through electrical cortical stimulation. Methods: Electrical cortical stimulation was applied to the occipital cortex and adjacent cortices using subdural grid electrodes in 23 epilepsy patients. Diverse visual responses were recorded. These responses were divided into different categories according to the specific response modalities, such as form, color, and motion. Form visual responses were further subdivided into simple, intermediate, and complex responses. The cortical localization of subdural electrodes was identified using MRI-CT coregistration. The cortical distribution of different visual responses was projected into three-dimensional surface renderings of the brain. The distribution and frequency of subdural electrodes showing different visual responses were quantified by calculating the percentage of the number of electrodes showing one specific type of visual response at the corresponding anatomic region to the total number of electrodes in all brain regions that produced the same response. Results: Simple form responses were obtained mostly at the occipital pole and the inferior occipital gyrus (47.4%) and the striate cortex (42.4%). Intermediate form responses occurred mainly on the peristriate cortex (52.5%) and the lateral occipital (28.0%) and fusiform gyri (19.5%). Complex forms were produced by stimulation of the basal temporo-occipital region (57.6%) and the lateral temporal or lateral temporo-occipital junctional region (42.4%). Color responses occurred on the basal occipital area, mostly at the fusiform (40.0%) and lingual gyri (36.0%). Moving sensations were evoked by stimulation of the basal temporo-occipital (28.4%) and the mesial parieto-occipital or temporo-parieto-occipital junctional regions (23.9%). Conclusions: Different modalities of vision, such as form, color, and moving sensation, appeared to be distributed and organized in different areas of the human visual cortex.

Hyperacusis, an increased sensitivity to auditory stimulation,1 may occur in patients with peripheral auditory system dysfunction, migraine, depression, and certain infectious diseases. However, hyperacusis is a rare manifestation of CNS lesions.2 Previous studies have reported paracusia (altered perception of loudness, timbre, or pitch) and palinacousis (perseveration of aural sensation) after medial geniculate body hemorrhage,3 auditory hallucination due to pontine hemorrhage,4 and bilateral hyperacusis due to caudal tectal hemorrhage.5 We report a unique patient presenting with unilateral hyperacusis due to a pontine hemorrhage. ### Case report. A 51-year-old hypertensive woman suddenly felt that environmental sounds were heard louder in her left ear than before. She said that “I feel as if an amplifier is inserted into my left ear hole.” At the same time, a machinery, “MRI noise-like” sound was heard in her left ear. She also had unpleasant tingling sensation in her left hemibody. On admission to a six-bed room of our hospital, she could not tolerate the noise, especially a loud, high pitched female voice, and requested us to move her to a more quiet two-bed room. She could not sleep in the left decubitus position, partly because tactile auricle stimulation aggravated the hyperacusis and tinnitus (allodynia) …

Sensory dysfunction in lateral medullary infarction (LMI) has been insufficiently studied. We prospectively analyzed the sensory signs of 50 consecutive patients with LMI, correlating them with MRI results. The classical ipsilateral trigeminal-contralateral body/limb pattern was observed only in 13 patients (26%) with lesions confined to the most posterolateral part of the caudal-middle medulla, whereas the bilateral trigeminal pattern observed in 12 patients was associated with large, ventrally extending lesions usually at the middle-rostral medulla. The contralateral trigeminal pattern was observed in nine patients with lesions sparing the most posterolateral area of the medulla. Isolated body/limb and isolated trigeminal involvement were observed in 10 and four patients respectively, usually associated with very small lesions. No sensory sign was noted in two patients. In addition to impaired sensation of spinothalamic modalities, six patients had decreased vibratory sensation in the hypoalgesic body/limb, whereas four patients had a lemniscal sensory deficit on the side contralateral to the hypoalgesic body/limb. Fifteen patients showed sensory gradient or level at the body/limb, and five had delayed appearance of sensory deficits. Trigeminal sensation was usually inhomogeneously involved among three divisions, which was more often of an onion-skin pattern than a divisional pattern. The perioral area, or V3, was generally spared or less severely involved on the side contralateral to the lesion. The sensory manifestations of LMI are extremely diverse and usually, although not always, correlate with MRI findings. The so-called classic, dissociated sensory pattern is actually uncommon, whereas sensory patterns previously thought of as atypical are relatively frequent.

To assess whether the thalamic pain syndrome of Dejerine-Roussy is produced preferentially by right diencephalic lesions and to elucidate its clinical features.Several experimental paradigms suggest that the right hemisphere is specialized for monitoring somatic states, including mediating pain. However, clinical studies of pain laterality have been inconclusive, possibly due to pathophysiologic diversity among analyzed patients. We collected reports of central pain laterality in a single, well-demarcated disorder, the Déjerine-Roussy syndrome.Reports from English, French, and German literature were identified through Medline search and bibliography-guided retrieval. Inclusion criteria were (1) thalamic lesion documented by CT, MRI, or postmortem examination and (2) contralateral pain. Exclusion criteria were (1) tumoral/nonvascular etiology (to optimize anatomic localization), (2) symptoms consisting solely of evoked dysesthesia without spontaneous pain, or (3) sidedness of lesion not clearly indicated. Cases were analyzed for laterality as well as secondary anatomic and clinical variables.Literature search identified 274 cases. After exclusions, 180 remained. A total of 114 had a right-sided thalamic lesion, 66 left-sided (p0.001). Laterality predominance was greater among men than women. The frequency of other components of the Dejerine-Roussy syndrome--sensory impairment, hemiparesis, ataxia, and choreoathetosis--did not significantly differ between right and left groups. Pain onset was within the first week poststroke in 36%. Frequency of spontaneous pain was 14% after any thalamic stroke and 24% after geniculothalamic artery territory stroke.Right-sided lesions predominate among reported cases of the thalamic pain syndrome. This preferential involvement of the nondominant thalamus in pain processing is supportive evidence of a nondominant hemisphere specialization in monitoring somatic states.

Axonal forms of autosomal dominant hereditary motor and sensory neuropathies (HMSNs) represent a heterogeneous group of disorders based on genetic linkage studies. We recently identified one large family with axonal HMSN exhibiting linkage to chromosome 3q, designated HMSN IIB, and report here the clinical and electrodiagnostic features. We clinically evaluated 10 individuals with HMSN IIB and performed detailed electrophysiologic studies in 5 of these patients. HMSN IIB is characterized clinically by the presence of distal symmetric motor weakness and prominent sensory loss affecting the lower extremities with preserved ankle reflexes. Symptomatic age at onset is in the second or early third decade of life. Six patients with HMSN IIB had distal trophic ulcerations in the feet, leading to eventual toe amputations in four cases. Electrodiagnostic studies confirmed a distal sensorimotor axonopathy involving the lower limbs with normal motor conduction velocities. Tibial H-reflexes were preserved in HMSN IIB, despite the uniform loss of sural nerve potentials. Overall, individuals with HMSN IIB demonstrated a consistent clinical and electrodiagnostic phenotype that had no overlap with genetically unaffected family members. The identification of specific clinical and electrodiagnostic features of HMSN IIB may prove useful in the diagnosis and differentiation between various subtypes of HMSN II.

A 50-year-old right-handed retired family business manager developed progressive left-sided weakness over 5 days after a mechanical fall. She remembered catching her foot on the carpet and falling down a flight of stairs, followed by severe neck pain over C4-C5 and inability to get up for nearly an hour. Over the subsequent month her symptoms progressed and she presented to the hospital with an asymmetric spastic paraparesis, loss of pinprick sensation in her arms and legs, loss of vibration sense to both hips, and double incontinence.

A 51-year-old woman with breast cancer presented with progressive numbness and burning in the right lower gum and oral mucosa. Neurologic examination was normal except for reduced sensation in the right lower gum region. Inferior alveolar neuropathy from mandible metastasis was diagnosed (figures 1 and 2). “Numb chin syndrome” is characterized by decreased sensation in the chin or lower lip, oral mucosa, and gum. Median time from cancer diagnosis is 45.8 ± 51 months.1 Median age is 48 years.1 It occurs in a variety of cancers, most commonly breast.2 Sites of neoplastic trigeminal nerve compression/infiltration include the skull base, leptomeninges, or mandible, the latter affecting the mental or inferior alveolar branches. Prompt diagnosis and treatment of the metastasis, typically with radiation therapy, can improve neurologic symptoms.

An 85-year-old man developed tingling in his feet, followed 1 week later by a similar sensation in both hands. He reported difficulty buttoning his shirt and unsteadiness when walking. There was no ascent of his symptoms proximal to the wrists and ankles. He denied pain, orthostasis, and bowel or bladder symptoms. He had had no prior similar symptoms, preceding illnesses, or recent changes in his health or medications. He had received the influenza vaccine 1 week prior to symptom onset.

Touch sensation is one element of sensory function. As such, somatosensation is one of the sensory domains included in the NIH Toolbox, which is an assessment battery for measuring a range of human functions including emotional health, sensation, cognition, and motor function. We evaluated a variety of methods for inclusion in the NIH Toolbox main battery. In a convenience sample of 409 participants, we evaluated aspects of kinesthesia, pain, and tactile discrimination. We present results on these measures across the lifespan and discuss implications for future studies that use the NIH Toolbox and these measures.

A 57-year-old man presented with spasms of his left jaw. Two years prior, he had developed left-sided facial numbness followed by development of left-sided shock-like pain and then involuntary and repetitive movements of the jaw-closing muscles. Jaw muscle contractions were episodic, interfered with chewing and talking, and led to frequent tongue biting. Individual spasms varied from seconds to minutes and he reported that function in between episodes was normal, although his wife felt he spoke with reduced mouth opening. He sometimes awoke with a bloody tongue, suggesting that contractions occurred during waking and sleep. He had no history of premonitory sensation or relief associated with the spasms. He reported no difficulty swallowing.

Ocular lateropulsion refers to directional bias of eye motion toward (ipsipulsion) or away from (contrapulsion) the lesion without limitation of eye motion.1,2⇓ In contrapulsion, the eyes deviate away from the side of the lesion.2,3⇓ Horizontal saccades toward the lesion side usually undershoot the target while saccades away from the side of the lesion overshoot the target. Medial medullary infarction (MMI) is characterized by a triad of contralesional hemiparesis, decreased position and vibration sensation in the contralateral side of the body, and ipsilesional tongue paralysis.3 We report ocular contrapulsion in a patient with rostral MMI. A 60-year-old man with a history of hypertension and diabetes presented with right-sided weakness and dysarthria. He showed rightward head tilt (figure, A), left beating nystagmus in the primary position, upbeating nystagmus in upward gaze, and ocular lateropulsion to the right (figure, C and D, and the video [available on the Neurology Web site at www.neurology.org]). Both eyes were orthotropic. He had right central type facial palsy and dysarthria. The tongue deviated to the right on protrusion (see figure, A). He also had right hemiparesis. The vibration and position sensation was impaired in the right side. Deep tendon reflexes were decreased bilaterally with positive Babinski sign in the right. He fell to the right on standing. Figure. (A) Photography of the head and both fundi of the patient. The patient shows rightward …

A 20-year-old man with neurofibromatosis I presented with back pain and altered sensation in the lower limbs without a radicular distribution and normal power. He subsequently developed urinary retention and reduced sensation …

A 49-year-old woman had received radiotherapy at the axillar, clavicular, and left laterocervical regions for Hodgkin lymphoma. Fifteen years later, she reported progressive loss of strength and sensation in her left arm. The patient had no …