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Hepatitis E virus (HEV)-associated neuralgic amyotrophy (NA) is often bilateral and severe, involving structures outside the brachial plexus, such as the phrenic nerves or the lumbosacral plexus. We report a case of an HEV-positive man who had presented with brachial neuritis, with significant phrenic nerve involvement, resulting in diaphragmatic paralysis requiring non-invasive ventilation. Prognosis of HEV-associated NA is often unfavourable and recovery is usually incomplete. Identifying HEV-associated NA early could potentially aid in prognostication and management planning, as clinicians and patients would be expectant of its potential features and severity. Respiratory function should be monitored in patients with HEV who suffer from NA, as diaphragmatic paralysis could potentially lead to severe respiration difficulties requiring ventilatory support.

BACKGROUND AND PURPOSE: The dopamine transporter scan or DaT scan is abnormal in presynaptic parkinsonism but normal in nondegenerative or postsynaptic parkinsonism. In this study, we tried to ascertain the impact of DaT scan on the diagnosis and clinical management and if the semiquantitative analysis of the DaT scans has any correlation with the clinical symptoms. METHODS: The electronic and nonelectronic records of patients of Plymouth Hospital NHS Trust, United Kingdom, from 2011 to 2015 were studied to find the indication, outcome, and the impact of the scan on the management of patients. The DaT scan results were assessed visually and semiquantitatively by the Department of Nuclear Medicine. The available data were statistically analyzed with the help of Microsoft XL2010 and GraphPad software. RESULTS: A total of 258 people had DaT scan. The scan results suggested an alternate diagnosis in 50.5% of clinically diagnosed patients with Parkinson disease. Similarly, DaT scan changed the diagnosis of 40% of patients with clinical diagnosis of vascular parkinsonism, 25% of clinically diagnosed drug-induced parkinsonism, and 54% of patients with possible Lewy body dementia. Visual assessment of the DaT scan revealed that more than 60% had grade 2 abnormalities. The distribution volume ratio, a semiquantitative tool for tracer uptake, was significantly less in the patients with akinetic-rigid subtype of Parkinson disease in comparison to a tremor predominant subtype. CONCLUSIONS: Dopamine transporter scan had a significant impact in diagnosis and management.

Autosomal recessive hereditary spastic paraparesis is rare.We present 4 patients with slowly progressive predominantly lower limb spasticity and ataxia. Only one patient had family history of ataxia but without any underlying diagnosis. All of them proved negative for the mutation of Spinocerebelalr ataxia genes SCA 1,2,3 and 6. All had mutation in the SPG 7 gene suggestive of autosomal recessive hereditary spastic paraparesis. One of the heterozygous mutatnts showed a novel c1617delC ,p(Val540fs) frameshift mutation in exon 12 of the SPG 7 gene. SPG7 mutation accounts for 1.5-7% of all the HSP but it is the cause of undiagnosed ataxia in 18.6% in a recent case series. SPG7 mutation should be remembered as an important cause of undiagnosed ataxia especially where next generation sequencing is not widely avaialbale or affordable.

Impulsive-compulsive behavior (ICB) in Parkinson's disease (PD) suggests a combination of impulse control disorders (ICDs), such as pathological gambling, hypersexuality, compulsive eating, excessive buying, and compulsive behaviors, such as punding, dopamine dysregulation syndrome (DDS), hoarding, and hobbyism. Hypersexuality and gambling are common in male patients while compulsive buying is common in women patients. Recent studies reveal the prevalence of ICB to be more than 25% among the PD patients. The nigrostriatal, mesocortical, and mesolimbic dopaminergic pathways play a crucial role in the pathogenesis of ICDs in PD patients. The greater tonic release of dopamine creates a state of relative dopamine deficit and reduced reward sensation and impulsive behaviors. The major risk factors for ICB are the use of dopamine agonist (DA), male gender, young patient, depression, smoking, drug abuse, Parkin mutation, and family history of ICDs. Single nucleotide polymorphism in dopamine receptors D1, D2, and D3 also acts as a major risk factor. Questionnaire for impulsive-compulsive disorders in PD is the most widely adopted screening tool for the detection of ICB in PD. The major treatment for PD is to discontinue DAs and use prolonged release formulation of the DAs. The role of deep brain stimulation (DBS) and apomorphine in the treatment of ICB is still uncertain. Though DBS can reduce the risk of DDS, it can precipitate new ICBs such as hypersexuality.

Aims: We studied the referral practice, reporting standards, and the impact of 123 ioflupane single photon emission computed tomogram dopamine transporters (DAT-SPECT) scans conducted for the diagnosis and clinical management of patients. Settings and Designs: The present study was a retrospective, non-interventional study. Materials and Methods: We assessed the DAT scan referral and the official reports available from the Nuclear Medicine Department of the Mater Misericordiae University Hospital over 1 year (2013). We also assessed the impact of the DAT scan result on the management of patients by analyzing patient records. The European Association of Nuclear Medicine Neuroimaging (EANM) 2010 and the Federal Drug Administration (FDA) 2012 guidelines were taken as the standard against which the quality of our DAT scans reporting was assessed. Statistical Methods: Microsoft Excel 2010 and graphpad software were used for statistical analysis. Results: Twenty five (56.2%) out of a total of 48 DAT scans were performed to confirm early Parkinson's disease, 5 (8.9%) were done to exclude drug-induced parkinsonism, and 8 (14.3%) to distinguish essential tremor from parkinsonism; 2 scans were performed to distinguish Lewy body diseases from Alzheimer's dementia, and 4 indications were outside the recommended guidelines. Twelve out of the 26 (46%) abnormal scans had bilateral abnormalities. Twenty one out of the 25 DAT scans proved the clinical diagnosis of degenerative parkinsonism to be correct. Conclusion: The overall compliance of the DAT imaging with the existing standard guidelines was good. DAT scan can be very useful in clinical practice because it influences the clinical diagnosis and management in 23% of the patients.

This sign is observed in atypical parkinsonism mainly in Progressive Supranuclear Palsy. The exact mechanism of this sign is not clear but the contraction of the Corrugator Supercilii muscle is the most important factor for the generation of vertical forehead creases. Though the wrinkling of forehead is a complex phenomenon involving multiple muscles but the 'Corrugator sign' would be a better term to describe this phenomenon. Despite the controversies regarding the mechanism and nomenclature, the 'Procerus sign' remains an important clinical clue for early Progressive Supranuclear palsy.

In this Teaching NeuroImage, Ferrer et al.1 described vertical gaze palsy and parkinsonism. Vertical gaze palsy, in this patient, is a consequence of compression of the mesencephalic rostral interstitial nucleus, the interstitial nucleus of Cajal, the posterior commissure, the periaqueductal gray matter, or interruption of the supranuclear inputs passing through the medial thalamus en route to the pretectal and prerubral areas.2,3 Though I agree that the most likely explanation of the bradykinesia and rigidity in this patient is secondary to midbrain compression and subsequent dopaminergic pathway degeneration,1 the authors did not demonstrate presynaptic dopaminergic pathway degeneration by SPECT imaging like dopamine transporters scan (DaT-SPECT scan) to support the hypothesis. More than 60%–70% of dopaminergic neurons degenerate before clinical signs of parkinsonism become evident. Though from the CT or MRI the extent of vascular lesions is not clear, significant frontal lobe atrophy is evident. Frontal lobe dysfunction or vascular parkinsonism can also lead to a clinically indistinguishable parkinsonism in this patient, so DaT scan would be helpful to identify the actual cause and management of his parkinsonism.4 Classically vascular or postsynaptic parkinsonism would give a normal DaT scan, but not nigrastriatal pathway degeneration secondary to compression by the giant perivascular or Virchow-Robin spaces.5

The interesting Teaching Video NeuroImage by Drs. Finlay and Yacovino1 demonstrated simultaneous soft palate and pharyngeal tremor and hypertrophic olivary degeneration (HOD). The palatal tremor is secondary to levator veli palatini contraction. The levator veli palatini is mainly supplied by the vagus nerve via the pharyngeal plexus. Most of the pharyngeal muscles are supplied by the vagus nerve, so simultaneous palate–pharyngeal tremor can be explained by the common nerve supply.