Biomedical subjects
Publications and source records attributed to H S Chandrashekar.
INTRODUCTION: Canavan disease is a megalencephalic leukodystrophy due to deficiency of the enzyme aspartoacylase. Proton MR spectroscopy finding of elevated N-acetyl-L: -aspartate is considered diagnostic of Canavan disease. CASE REPORT: We report a case of Canavan disease, which showed restricted diffusion in diffusion-weighted imaging and discuss the cause of it.
Racemose cysticercal cyst is the subarachnoid manifestation of the larvae of Taenia solium. On MRI the cysts may resemble other cystic masses. We report the magnetic resonance spectroscopy (MRS) features of a case on in vivo proton spectroscopy and discuss its role in the diagnosis of intracranial cysts of parasitic aetiology.
Megalencephalic leukoencephalopathy with subcortical cysts (MLC) is a rare, recently described disease. It is characterized clinically by a large head, mild neurological symptoms and a remarkably slow course of functional deterioration. The MRI is characterized by 'swollen white matter' and large symmetrical cystic changes in the cerebral hemispheres. MLC should be considered in the differential diagnosis of children with megalencephaly and leukoencephalopathy. We report a child with this disease and discuss the MRI and MRS features.
Intracranial metastases of central nervous system are relatively common in patients with systemic cancer. Computed tomography (CT) scans of 60 patients of intracranial metastatic disease of unknown primaries, at the time of surgery, were retrospectively analyzed. These patients primarily presented with neurological dysfunction. They were operated upon for various reasons and histopathological diagnosis was obtained. There were 39 male and 21 female patients, with age range of 18 to 74 years. The common clinical symptoms were raised intracranial pressure without lateralization, acute onset hemiplegia and seizures. Multiple cranial nerve palsies were observed in 4 patients. Histopathologically the intracranial lesions consisted of metastatic adenocarcinoma (32 cases) or metastatic squamous cell carcinoma (28 cases). Among cases of adenocarcinoma, CT revealed solitary lesions in 17 and multiple lesions in 13 cases. Two had extraaxial deposition in the region of petrous apex. Out of squamous cell carcinomas, 17 lesions were solitary, while 10 were multiple and one had extraaxial deposition in the region of petrous apex. This study is unique as it consisted of CT features of intracranial metastases of unknown primary malignant disease elsewhere in the body.
A 56 year old man presented with acute onset posterior column and lateral spinothalamic tract dysfunction over a period of 15 days. MRI showed diffuse hyperintensity on T2WI involving the posterior columns. A diagnosis of subacute combined degeneration (SCD) of the spinal cord was considered and confirmed by laboratory findings. The patient showed complete recovery on B12 therapy. MRI lesion also compeletely resolved.