Biomedical subjects

S Shashank

Publications and source records attributed to S Shashank.

3 recordsLinked to original sources

PubMed1999

Parkinsonism due to predominant involvement of substantia nigra in Japanese encephalitis.

OBJECTIVE: To study the clinical correlates of lesions seen predominantly in the substantia nigra in some patients with Japanese encephalitis (JE). BACKGROUND: JE typically involves thalamus, brainstem, spinal cord, and cerebral cortex. Rarely, basal ganglia and cerebellum may be affected. Lesions are often widespread and discrete. Predominant involvement of substantia nigra in JE has not been previously reported. METHODS: Of 52 patients with JE seen in an endemic zone, five were selected on the basis of isolated lesions in the substantia nigra on MRI; all were subjected to detailed clinical and laboratory evaluation. RESULTS: Presenting symptoms were fever, alteration of consciousness, neck stiffness, and decreased body movements. Examination during acute illness revealed restricted eye movements, opsoclonus, upbeating nystagmus, and cogwheel rigidity. There was early and complete recovery of consciousness and eye signs. Parkinsonian features such as positive glabellar tap sign, masklike face, bradykinesia, tremors, and postural instability became apparent as these patients started walking. Reversible mutism was observed in three patients during the acute phase. Response to levodopa, amantadine, and trihexiphenedyl was partial. Three patients were followed for more than 1 year, during which time their parkinsonian features recovered completely. Substantial recovery was also observed in the two other patients 2 months after regaining consciousness. CONCLUSIONS: Some patients with Japanese encephalitis may have lesions predominantly in the substantia nigra. After recovery from acute encephalitic illness, they manifest clinically with typical parkinsonian features. Although several viruses are known to cause parkinsonism, this is the first demonstration of a virus producing lesions predominantly in the substantia nigra and causing parkinsonism.

Adolescent↗

PubMed1999

Intravenous immunoglobulin therapy in acute disseminated encephalomyelitis.

We describe 4 patients with acute disseminated encephalomyelitis (ADEM) who were treated with intravenous immunoglobulins (IVIg) after getting no immediate response from a 3-5 day course of high dose intravenous methylprednisolone. All had clinical features to suggest poor prognosis and MRI findings to indicate extensive white matter changes in the brain. Two patients who had spinal cord involvement as well, required ventilatory support during acute phase of the illness. All the 4 patients recovered dramatically. Recovery pattern suggested that IVIg might be useful in fulminant ADEM. Further trials are needed to look for the efficacy of IVIg alone and in combination with methylprednisolone in the treatment of ADEM.

Adolescent↗

PubMed1998

Parainfectious conus myelitis.

We describe electroclinical and imaging features of a peculiar type of parainfectious myelitis that selectively involves the conus/epiconus region of the spinal cord. Twelve patients of parainfectious myelitis with MRI evidence of inflammatory lesions in the conus/epiconus region of the spinal cord were studied. All patients underwent full clinical and electrophysiological evaluation along with MRI of the spine. MRI included axial images at the site of lesion. All patients had a unique clinical presentation with urinary symptoms. Careful clinical examination revealed minimal sensorimotor dysfunction in the lower lumbar and sacral segments, which remained unnoticed by most of the patients; three female patients had no sensorimotor deficit. The motor paralysis recorded in four patients was flaccid and areflexic. The sensory level was inconspicuous as it was in the leg area corresponding to the lumbar and sacral spinal segments. Sensory loss was significantly more in the perineal region in those seven patients who had MRI evidence of inflammatory lesion in conus medullaris; two patients had maximum sensory loss in lumbar dermatomal distribution, which corresponded with the focal segmental myelitis involving 'epiconus'. MRI done in the sagittal plane was either normal or only 'suggestive' of myelitis in most of the patients and the inflammatory lesions were much more visible in the axial plane. The lesions predominantly involved central gray matter with spread to adjoining white matter in nine patients; in three patients with pure bladder involvement, lesions were confined to lateral gray matter of the conus medullaris. Our findings indicate that parainfectious myelitis (PIM) selectively involving conus medullaris is an important cause of unexplained acute or sub-acute urinary symptoms in adolescent and adult patients. In suspected cases, MRI must include axial images of the conus-epiconus region, as sagittal images may not always reveal the lesion. Due to initial presentation with urinary symptoms, absent or minimal sensory-motor signs, no transverse level over the trunk and unique MRI features, this condition may be called parainfectious conus myelitis (PICM).

Acute Disease↗