ALS Regional Variants (Brachial Amyotrophic Diplegia and Amyotrophic Leg Diplegia): Still A Diagnostic Challenge in Neurology.

PURPOSE: We illustrate three patients with regional amyotrophic lateral sclerosis (ALS) variants and hope to improve accuracy in diagnosis for this scarce group of diseases. CASE REPORT: Amyotrophic lateral sclerosis (ALS) represents a broad spectrum of acquired and inherited neurodegenerative conditions involving the upper and motor neurons. Typical ALS remains a clinical diagnosis that is not hard to diagnose. Still, when it comes to atypical forms of ALS, the physicians may face some difficulties differentiating between atypical forms of ALS and other neurological diseases, such as multifocal motor neuropathy, chronic inflammatory demyelinating polyneuropathy, and spinal muscular atrophy. Both brachial amyotrophic diplegia (BAD) and leg amyotrophic diplegia (LAD) are considered regional variants of ALS. We are here to report two cases of BAD and one case of LAD. All these 3 cases showed progression of the disease after longitudinal follow- up for approximately two years. However, after two years, their disease progressions were slow and confined to their 'regions' of upper or lower limbs. CONCLUSION: BAD and LAD are unique regional variants of ALS with a significantly better prognosis than typical ALS. The phenotypic characteristics of regional ALS variants must be recognized when physicians are to tailor advice on disease progression, disease outcome, drug therapy, and end-of-life planning for patients with ALS or ALS variants.

Right Fusiform Gyrus Infarct with Acute Prosopagnosia.

A 56-year-old, right-handed man with no known past medical history presented with sudden onset of inability to recognize familiar individuals in person, including his wife and his mother. He also couldn't recognize himself in the mirror. There was no weakness, numbness, visual disturbances, or speech difficulty. Face recognition test, using Warrington Recognition Memory Test (1), showed the presence of complete prosopagnosia. The rest of the neurological and cranial nerves examinations were normal. Magnetic resonance imaging (MRI) of the brain showed restricted diffusion at the right temporal and occipital lobes (the fusiform gyrus) [Figure 1]. Magnetic resonance angiogram (MRA) of the brain was unremarkable. The 24-hours Holter monitoring showed paroxysmal atrial fibrillation. The transthoracic echocardiogram and carotid doppler ultrasound scan were normal. He was then treated with rivaroxaban 20mg daily for secondary stroke prevention in non-valvular atrial fibrillation. Face recognition skill training was started in the ward, which includes compensatory strategies to achieve person recognition by circumventing the face processing impairment, and remediation to enhance mnemonic function for face recognition. His prosopagnosia resolved completely after one week. Prosopagnosia, also known as face blindness, is an impairment in recognizing faces. The core defects are the loss of familiarity with previously known faces and the inability to recognize new faces. Patients with prosopagnosia may present with poor recognition of familiar individuals in person or in the photograph, confusion with plotlines in movies or plays with numerous characters, and difficulty distinguishing individuals wearing a uniform or similar clothing. Stroke is the most common cause of acquired prosopagnosia (2). Other less common aetiologies include traumatic brain injury, carbon monoxide poisoning, temporal lobectomy, and encephalitis. Literature has shown that areas involved in acquired prosopagnosia are the right fusiform gyrus or anterior temporal cortex, or both (3). The fusiform gyrus is part of the lateral temporal lobe and occipital lobe in 'Brodmann area 37' (4). The fusiform gyrus is considered a key structure for functionally specialized computations of high-level vision such as face perception, object recognition, and reading. Individuals with fusiform lesions are more likely to have apperceptive prosopagnosia, while those with anterior temporal lesions have an amnestic variant (5). In summary, prosopagnosia can be the sole presentation for the right fusiform gyrus stroke. It is important to recognize prosopagnosia for early stroke diagnosis and avoid misdiagnosing it as a psychiatric or ocular disorder. Keywords: prosopagnosia, fusiform gyrus, stroke.

Evaluation of trigeminal nerve tractography using two-fold-accelerated simultaneous multi-slice readout-segmented echo planar diffusion tensor imaging.

OBJECTIVES: Simultaneous multi-slice (SMS) imaging with short repetition time (TR) accelerates diffusion tensor imaging (DTI) acquisitions. However, its impact when combined with readout-segmented echo planar imaging (RESOLVE) on the cranial nerves given the challenging skull base/posterior fossa terrain is unexplored. We evaluated the reliability of trigeminal nerve DTI metrics using SMS with RESOLVE-DTI. METHODS: Eight healthy controls and six patients with unilateral trigeminal neuralgia (TN) underwent brain MRI scan. Three different RESOLVE-DTI protocols were performed on a 3-T MRI system: non-SMS (TR = 4330 ms), SMS with identical TR (4330 ms), and SMS with short TR (2400 ms). Pontine signal-to-noise ratio (SNR) and DTI metrics of the trigeminal nerve streamlines tracked by two independent raters using deterministic tractography and standardized tracking protocol were obtained. These were statistically analyzed and compared across the three protocols using intra-rater and inter-rater intraclass correlation coefficients (ICCs), one-way analysis of variance (ANOVA), post hoc analysis, and linear regression. RESULTS: On visual screening, there were no artifacts across the trigeminal nerves. All data also cleared objective image quality assurance analysis. Pontine SNR was similar for the two SMS protocols and higher for the non-SMS RESOLVE-DTI (F(2,36) = 4.40, p = 0.02). Intra-rater and inter-rater ICCs were very good (> 0.85). Trigeminal nerve DTI metrics were consistently measured by the three protocols, revealing significant linear relationships between non-SMS- and SMS-derived DTI metrics. CONCLUSION: SMS RESOLVE-DTI enables fast and reliable evaluation of microstructural integrity of the trigeminal nerve, with potential application in the clinical management of TN. KEY POINTS: • Readout-segmented diffusion-weighted echo planar imaging (RESOLVE-DTI) reduces image distortion artifacts in the posterior fossa but its long acquisition time limits clinical utility. • Simultaneous multi-slice (SMS) imaging combined with RESOLVE-DTI provides reliable trigeminal nerve tractography with potential applications in trigeminal neuralgia. • Two-fold-accelerated RESOLVE-DTI yields comparable trigeminal nerve streamlines and DTI metrics while near-halving acquisition time.

Paroxysmal hemicrania masquerading as a stroke in an elderly gentleman: case report.

BACKGROUND: Paroxysmal hemicrania has not been associated with ipsilateral weakness, loss of sensation and Horner's syndrome. This report is the first of its kind documented in literature. CASE PRESENTATION: This was an elderly, sixty-five-year-old Chinese male who presented with a headache fulfilling criteria of paroxysmal hemicrania and was found to have signs of ipsilateral conjunctival injection, Horner's syndrome, weakness and loss of sensation; with resolution of the patient's physical signs after relief of the headache. Brain magnetic resonance imaging did not show any strokes or other headache mimics. The patient had a marked response to indomethacin and a decrease of headache intensity and frequency with indomethacin prophylaxis. CONCLUSIONS: Paroxysmal hemicrania has joined the list of stroke chameleons and that it would be one of the differentials in a patient with hemiplegia, hemisensory loss, autonomic signs and severe headache. It suggests that paroxysmal hemicrania in the elderly present atypically.

Multiple sclerosis with intractable vomiting and atypical area postrema lesion.

BACKGROUND: Area postrema syndrome is considered as one of the most typical presentations of neuromyelitis optica spectrum disorders (NMOSDs) (Wingerchuk et al., 2015). The involvement of area postrema is rarely seen in multiple sclerosis (MS). We are here report a case of a young woman with multiple sclerosis, presented with intractable vomiting, and her MRI brain showed acute T2 hyperintense signal over the area postrema. CASE PRESENTATION: A 36-year-old Asian woman who is known to have schizophrenia and multiple sclerosis since 2012. She was noted to have spastic gait, and the MRI brain in 2012 showed multiple perpendicular periventricular T2 lesions suggestive of multiple sclerosis (MS). However, she defaulted her neurologist follow-up and was not on any treatment for MS. She was admitted in 2016 with intractable vomiting, and her MRI brain showed T2 hyperintense signal over area postrema with focal contrast enhancement. Her MRI cervical spine was normal. The visual evoked potential study showed bilateral prolonged P100 latencies. Oligoclonal bands were detected in her CSF analysis. Both the serum aquaporin-4 IgG (AQP4 IgGs) antibody and myelin oligodendrocyte glycoprotein (MOG-IgGs) were negative. Her intractable vomiting resolved after a short course of intravenous methylprednisolone. She was treated as MS with interferon-beta 1a. She has been in remission since 2016, and her functional status also improved from the expanded disability status scale (EDSS) of 2.0 (in 2016) to 1.0 (in 2020). CONCLUSION: We proposed that although area postrema lesion is typically seen in NMOSDs, it may also be seen in MS. Current MRI criteria for MS and NMOSDs are not sufficiently specific, and the diagnostic criteria should only be used in the appropriate clinical context.