Extrapontine Myelinolysis and Reversible Parkinsonism After Hyponatremia Correction in a Case of Pituitary Adenoma: Hypopituitarism as a Predisposition for Osmotic Demyelination.

BACKGROUND: Osmotic demyelination syndrome commonly follows rapid correction of hyponatremia. Although pons is a common location, extrapontine locations, such as striatum and thalamus, have been reported. CASE DESCRIPTION: A 48-year-old woman presented with masked facies, shuffling gait, and pill-rolling tremors suggestive of acute-onset parkinsonism. Hyponatremia was diagnosed following a bout of diarrhea, which was corrected with hypertonic saline. Magnetic resonance imaging of the brain showed a giant pituitary adenoma. Hyperintensities on T2-weighted imaging were also seen at the level of pons and bilateral striatum. Central pontine myelinolysis and extrapontine myelinolysis were diagnosed. Hormonal assay showed hypocortisolism, secondary hypothyroidism, and hypogonadism. The patient was started on levodopa-carbidopa, steroids, and thyroxine. She underwent transnasal pituitary adenoma excision. At 6 months postoperatively, she had recovered completely with normal gait. Repeat imaging showed complete resolution of myelinolysis. At 36 months, she continued to have hypocortisolism and hypothyroidism requiring replacement. CONCLUSIONS: Extrapontine myelinolysis with parkinsonism and asymptomatic central pontine myelinolysis is rare with few cases described in the literature. Our patient had a pituitary adenoma with hyponatremia requiring sodium correction, and we believe that hypopituitarism might have predisposed her to osmotic demyelination. We reviewed relevant literature on extrapontine myelinolysis in suprasellar tumors and the pathophysiology. Hypopituitarism is an underrecognized cause of hyponatremia. When treating a patient with hyponatremia, knowing the pituitary function status is a prerequisite for the physician to prevent osmotic demyelination syndrome.

Giant posterior fossa dural cavernoma in a child.

PURPOSE: Extra-axial (dural) cavernomas are rare and constitutes 5% of all cavernomas. They are thought to arise from the venous plexus of the dura. They can reach large sizes before diagnosis and can have an aggressive presentation. METHODS: The authors report a rare case of giant cavernoma based on the posterior fossa dura adjacent to the sigmoid sinus (sino-dural angle) in an 8-year-old boy which was excised with good outcome. The authors describe its clinico-radiological profile and outcome characteristics along with a comprehensive review of relevant literature. RESULTS: This child underwent retromastiod craniectomy and complete excision of the dural cavernoma. The dural attachment was coagulated. Histopathological examination confirmed the diagnosis. CONCLUSION: We report cavernoma needs to be considered in the differential diagnosis of a dural-based posterior fossa lesion in paediatric population as complete excision is possible.

An equiosmolar study on early intracranial physiology and long term outcome in severe traumatic brain injury comparing mannitol and hypertonic saline.

The impact of hypertonic saline (HTS) on long term control of intracranial hypertension (ICH) is yet to be established. The current prospective randomized controlled study was carried out in 38 patients with severe traumatic brain injury (TBI). Over 450 episodes of refractory ICH were treated with equiosmolar boluses of 20% mannitol in 20 patients and 3.0% HTS in 18 subjects. Intracranial pressure (ICP) was monitored for 6days. ICP and cerebral perfusion pressure (CPP) were comparable between the groups. The mannitol group had a progressive increase in the ICP over the study period (p=0.01). A similar increase was not seen in the HTS group (p=0.1). The percentage time for which the ICP remained below a threshold of 20 mmHg on day6 was higher in the HTS group (63% versus 49%; p=0.3). The duration of inotrope requirement in the HTS group was less compared to the mannitol group (p=0.06). The slope of fall in ICP in response to a bolus dose at a given baseline value of ICP was higher with HTS compared to mannitol (p=0.0001). In-hospital mortality tended to be lower in the HTS group (3 versus 10; p=0.07) while mortality at 6 months was not different between the groups (6 versus 10; p=0.41). Dichotomized Glasgow Outcome Scale scores at 6months were comparable between the groups (p=0.21). To conclude, immediate physiological advantages seen with HTS over mannitol did not translate into long term benefit on ICP/CPP control or mortality of patients with TBI.

Managing a Rare Malignant Sweat Gland Tumor Invading the Brain: Case Report and Literature Review.

BACKGROUND: Malignant sweat gland adnexal tumors are rare with an incidence of 0.001%. Of these, clear cell hidradenocarcinoma is an extremely uncommon subtype that accounts for 6% of malignant eccrine sweat gland tumors. They occur commonly in the head, neck, and extremities. Although they have a propensity for local recurrence, intracranial extension with brain invasion is extremely rare. CASE DESCRIPTION: We report a 76-year-old man with a large, recurring, ulcerated, fungating scalp swelling of 14 years who presented with focal seizures and drowsiness. Neuroimaging revealed a massive tumor arising from the scalp to invade the left parietal lobe and extending to the right side with occlusion of the superior sagittal sinus. The overlying parietal bone was lytic with a "moth-eaten" appearance. He underwent wide excision of the scalp lesion, near-total cerebral tumor decompression followed by titanium mesh cranioplasty, rotation flap reconstruction of the scalp, and adjuvant radiotherapy to the skull vault. Histopathology revealed clear cell hidradenocarcinoma. Whole-body positron emission tomography scan did not reveal any other lesion. At 24 months' follow-up, he remains recurrence free. CONCLUSION: We report a rare indolent case of clear cell hidradenocarcinoma invading the brain, which was managed with near-total decompression and adjuvant radiotherapy. Intracranial extension in such aggressive tumors poses challenges in management, and regular neuroimaging surveillance is advised.

Paediatric calcified intramedullary schwannoma at conus: A common tumor in a vicarious location.

Spinal schwannomas are commonly intradural extramedullary in location. As Schwann cells are not common in the central nervous system, intramedullary schwannomas are a rare entity. In adults, an estimated sixty cases have been reported in English literature. They are rarer in children (less than ten cases), and preoperative diagnosis becomes a prerogative in achieving total excision. Cervical cord is a common location and less commonly they occur in the conus. We report a rare case of calcified conus intramedullary schwannoma in a child without neurofibromatosis, who presented with conus-cauda syndrome of 1-year duration. Literature has been reviewed regarding its origin, pathophysiology, radiological features, and surgical management. This child underwent laminotomy and subtotal resection of the lesion. Histopathologically, tumor had typical features of schwannoma and was positive for S-100 immunoperoxidase. We believe that schwannoma needs to be considered in the preoperative differential diagnosis of a conus tumor in children as complete excision is possible in these benign tumors, thus affecting a cure.