Differentiation of dementia with Lewy bodies, Alzheimer's disease and vascular dementia by cardiac 131I-meta-iodobenzylguanidine (MIBG) uptake (preliminary report).

OBJECTIVE: Differentiation of dementia with Lewy bodies (DLB), vascular dementia (VAD), and Alzheimer's disease (AD) is difficult in clinical practice. Several new techniques have been used for differentiation of various types of dementia. Among these techniques 123I-meta-iodobenzylguanidine (MIBG) uptake was reported to have benefit in distinguishing DLB from AD. The authors study the role of MIBG as a tool for differentiation of DLB, AD and VAD. METHOD: Patients with dementia were recruited to the study by DSMIIIR criteria. Diagnosis of each dementia type was made by standard clinical criteria. Brain imagings and 131I-MIBG uptake were performed in all the studied patients. RESULTS: Five DLB, 3 AD and 3 VAD patients were clinically diagnosed. The heart/mediastinum (H/M) ratio in 4 out of 5 in DLB was significantly lower than H/M ratio in patients with AD and VAD. AD patients had the highest uptake of MIBG MIBG uptake of VAD patients was in the range between AD and DLB but the values were close to the AD group. CONCLUSIONS: 131I-MIBG is helpful in differentiating DLB from AD.

Episodic ataxia type 2: an uncommon inherited CNS channelopathies.

The author reports the first Thai patient with a rare inherited ataxic disorder characterized by intermittent episodes of ataxia, headache and vertigo. The patient was well between attacks despite persistent nystagmus on examination. Magnetic resonance imaging of the brain revealed cerebellar atrophy. All symptoms were ameliorated by acetazolamide therapy. This clinical syndrome was previously described as acetazolamide-responsive episodic ataxia which was subsequently shown to be associated with mutations in a alpha1A-subunit of P/Q type voltage-gated calcium channel gene, known as 'episodic ataxia type 2'. Clinical and molecular aspects of episodic ataxia type 2 were also reviewed.

Detection of JC virus infection in progressive multifocal leukoencephalopathy: the first documented case in Thailand.

Progressive Multifocal Leukoencephalopathy (PML) is a demyelinating brain disease caused by human polyoma JC virus (JCV). This disease is an important cause of morbidity and mortality in AIDS patients. Definite diagnosis currently requires a brain biopsy. PCR for JCV of CSF, an emerging diagnostic tool, has a high specificity for the diagnosis of PML in patients with characteristics on clinical and neuroradiological findings. The authors report a 36-year-old woman who presented with prolonged fever, progressive weakness, and slow speech for 2 months. Clinical features and MRI findings were compatible with PML. Qualitative PCR for JCV of CSF showed a positive result. This report emphasizes the yield of PCR, the CSF for JCV in a diagnosis of PML, which may reduce the need for a brain biopsy in such cases.