Paroxysmal dysarthria-ataxia syndrome: Literature review on MRI findings and report of a peculiar case with clinically isolated syndrome coexisting with anti-N-methyl-d-aspartate receptor antibodies.

Paroxysmal dysarthria and ataxia (PDA) syndrome constitutes a rare neurological disorder, and is generally reported in cases of multiple sclerosis (MS) involving the midbrain. We present an illustrative case of 32-year-old female who developed clinically isolated syndrome manifested paroxysmal dysarthria, ataxia, ptosis and diplopia, coexisting with anti-N-methyl-d-aspartate receptor antibodies. We review the literature and identify 23 other cases with brain MRI examinations to summarize the lesion locations and clinical characteristics of PDA syndrome, and ultimately provide a new framework for understanding this rare condition. The current case expands the spectrum of symptoms in PDA syndrome, which was including but not limited to dysarthria and ataxia. Caudal paramedian midbrain lesions involving decussation of the superior cerebellar peduncles appear to be critical for PDA syndrome.

Refractory hepatic encephalopathy in a patient with hypothyroidism: Another element in ammonia metabolism.

Hepatic encephalopathy (HE) remains a diagnosis of exclusion due to the lack of specific signs and symptoms. Refractory HE is an uncommon but serious condition that requires the search of hidden precipitating events (i.e., portosystemic shunt) and alternative diagnosis. Hypothyroidism shares clinical manifestations with HE and is usually considered within the differential diagnosis of HE. Here, we describe a patient with refractory HE who presented a large portosystemic shunt and post-ablative hypothyroidism. Her cognitive impairment, hyperammonaemia, electroencephalograph alterations, impaired neuropsychological performance, and magnetic resonance imaging and spectroscopy disturbances were highly suggestive of HE, paralleled the course of hypothyroidism and normalized after thyroid hormone replacement. There was no need for intervention over the portosystemic shunt. The case findings support that hypothyroidism may precipitate HE in cirrhotic patients by inducing hyperammonaemia and/or enhancing ammonia brain toxicity. This case led us to consider hypothyroidism not only in the differential diagnosis but also as a precipitating factor of HE.

From dizziness to severe ataxia and dysarthria: New cases of anti-Ca/ARHGAP26 autoantibody-associated cerebellar ataxia suggest a broad clinical spectrum.

In 2010, a novel anti-neuronal autoantibody, termed anti-Ca, was described in a patient with subacute cerebellar ataxia, and Rho GTPase-activating protein 26 (ARHGAP26) was identified as the target antigen. Recently, three additional cases of anti-Ca-positive cerebellar ataxia have been published. In addition to ataxia, cognitive decline and depression have been observed in some patients. Here, we report two new cases of anti-Ca-associated autoimmune cerebellar ataxia. Patient 1 presented with dizziness and acute yet mild limb and gait ataxia. Symptoms stabilized with long-term oral corticosteroid therapy but transiently worsened when steroids were tapered. Interestingly, both initial occurrence and worsening of the patient's neurological symptoms after steroid withdrawal were accompanied by spontaneous cutaneous hematomas. Patient 2 initially presented with an increased startle response and myoclonic jerks, and subsequently developed severe limb and gait ataxia, dysarthria, oculomotor disturbances, head and voice tremor, dysphagia, cognitive symptoms and depression. Steroid treatment was started five years after disease onset. The symptoms then responded only poorly to corticosteroids. At most recent follow-up, 19 years after disease onset, the patient was wheelchair-bound. These cases extend the clinical spectrum associated with anti-ARHGAP26 autoimmunity and suggest that early treatment may be important in patients with this rare syndrome.

The first case report of neuroacanthocytosis in Thailand: utilization of a peripheral blood smear technique for detecting acanthocytes.

BACKGROUND: Neuroacanthocytosis (NA) is a heterogeneous group of hereditary syndromes characterized by the association of neurological abnormalities with acanthocytosis. Among those, chorea-acanthocytosis (ChAc) is the most frequent form, manifested by predominant orofacial dyskinesias associated with marked dysarthria and dysphagia. PURPOSE: To describe the first known case of ChAc in Thailand. METHODS AND RESULTS: A 40-year-old man presented with "core features" of NA which led to a high level of suspicion of this syndrome. An initial dry blood smear did not reveal acanthocytes but by utilizing diluted blood combined with a wet blood smear, which is accepted as the clinical gold standard when combined with an examination, acanthocytes were detected. CONCLUSION: Diagnosis of NA is possible without molecular diagnostics by relying on a high degree of clinical suspicion of characteristic clinical features and a standardized wet blood smear method of peripheral blood examination for acanthocytes.

Localized reversible reduction of apparent diffusion coefficient in transient hypoglycemia-induced hemiparesis.

BACKGROUND AND PURPOSE: The pathophysiology of hypoglycemia shares a common mechanism with cerebral ischemia, but so far, little is known regarding MRI of humans with hypoglycemia. METHODS: We report a patient with left hemiparesis and dysarthria associated with a blood glucose level of 1.7 mmol/L. The patient recovered completely after glucose infusion. RESULTS: The initial diffusion-weighted imaging (DWI) showed increased signal intensities and a reduction of apparent diffusion coefficient (ADC) values localized in the corpus callosum (splenium) and asymmetrically in the corona radiata. After 48 hours, follow-up revealed complete recovery of DWI and ADC signal abnormalities. CONCLUSIONS: To our knowledge, this is the first presentation of a case with transient hypoglycemia-induced focal neurological deficits revealing completely reversible MRI changes in terms of disturbed DWI and ADC with a peculiar as yet undescribed topography.