M.C. Sharma

Cerebellopointine angle medulloblastoma

Cerebellopontine angle (CPA) medulloblastoma is a rare tumour. To date, only 19 cases have been reported over a period of 8 years, we have treated 14 cases of CPA medulloblastomas. This is first and the largest series of CPA medulloblastomas reported in the world literature.

Effect of posture on mouth opening and modified Mallampati classification for airway assessment

Several bedside airway assessment methods have been proposed for preoperatively identifying patients who are difficult to intubate. To date, the Mallampati grading remains a time-tested technique for difficult airway assessment. Both Mallampati and the further modification by Samsoon and Young assessed patients in the seated position. During clinical practice, situations may arise where it may not be feasible for the patient to sit up for airway assessment. The aim of our prospective study was to determine whether there was any difference between the sitting and supine positions for the assessment of Mallampati grade. Eighty adult patients of American Society of Anesthesiologists (ASA) physical status I and II, aged 18–65 years, admitted to our neurosurgical ward were enrolled and assessed for airway. Our study revealed that change in posture produced a significant change in the mouth openings and Mallampati grades of the patients. This change was always toward a higher grade when the patient was turned supine from the sitting position.

Pituitary abscess associated with prolactinoma

We present a 37-year-old female, who was admitted with a long standing history of menstrual abnormalities and galactorrhoea followed by progressive visual loss. X-ray of the skull showed an enlarged sella with destruction of the floor. CT scan of the head revealed a giant pituitary adenoma with sellar and parasellar extension. At surgery, through a transsphenoidal approach, solid tissue and cystic areas containing pus from which Escherichia coli was cultured were encountered. She had an uneventful postoperative recovery. At 2 years follow up, she was doing well.

Malignant paraganglioma of the sellar region mimicking a pituitary macroadenoma

We report a case of malignant sellar and suprasellar paraganglioma presenting as pituitary macroadenoma, causing headache and visual deficits. The characteristics of this tumor at this rare location are discussed.

Clinical spectrum of Hallervorden-Spatz syndrome in India.

Hallervorden-Spatz syndrome is a rare autosomal recessive disorder that involves progressive extrapyramidal manifestations. Classical and atypical clinical presentations are known. Clinical details of patients admitted to the neurology ward or attending the movement disorder clinic of the All India Institute of Medical Sciences between January 2001 and July 2007 were reviewed. Sixteen patients (9 males and 7 females) were included in the study (median age 14 years; range 6-25). The most common clinical presentation was limb or cranial onset progressive dystonia. The patients with early onset had more frequent truncal and axial dystonia, including retrocollis, oromandibular-facial dystonia and chorea, dysarthria, pyramidal signs, gait disturbance, cognitive impairment, delay in milestones, retinitis pigmentosa, optic atrophy, oculomotor abnormalities, positive family history and acanthocytosis. Although rare, cerebellar ataxia, behavioural abnormalities, parkinsonism and apraxia of eyelid opening were exclusively seen in late onset patients. The present study highlights the heterogeneity of this disease entity and also describes certain unusual clinical features.

Primary central nervous lymphoma presenting as bilateral cerebellopontine angle lesions: a rare case report

The authors describe a rare case of primary central nervous system (CNS) lymphoma presenting as bilateral cerebellopontine angle lesions. Imaging showed bilateral cerebellopontine angle lesions and also a small mass in right lateral ventricle and anterior third ventricle region. The right cerebellopontine angle mass was surgically excised and radio- and chemotherapy given for the remaining lesions. This is the second case reported in the world literature. The case is discussed and the literature is reviewed.

DECT evaluation of noncalcified coronary artery plaque

PURPOSE Composition of the coronary artery plaque is known to have critical role in heart attack. While calcified plaque can easily be diagnosed by conventional CT, it fails to distinguish between fibrous and lipid rich plaques. In the present paper, the authors discuss the experimental techniques and obtain a numerical algorithm by which the electron density (ρ(e)) and the effective atomic number (Z(eff)) can be obtained from the dual energy computed tomography (DECT) data. The idea is to use this inversion method to characterize and distinguish between the lipid and fibrous coronary artery plaques. METHODS For the purpose of calibration of the CT machine, the authors prepare aqueous samples whose calculated values of (ρ(e), Z(eff)) lie in the range of (2.65 × 10(23) ≤ ρ(e) ≤ 3.64 × 10(23)/cm(3)) and (6.80 ≤ Z(eff) ≤ 8.90). The authors fill the phantom with these known samples and experimentally determine HU(V1) and HU(V2), with V1,V2 = 100 and 140 kVp, for the same pixels and thus determine the coefficients of inversion that allow us to determine (ρ(e), Z(eff)) from the DECT data. The HU(100) and HU(140) for the coronary artery plaque are obtained by filling the channel of the coronary artery with a viscous solution of methyl cellulose in water, containing 2% contrast. These (ρ(e), Z(eff)) values of the coronary artery plaque are used for their characterization on the basis of theoretical models of atomic compositions of the plaque materials. These results are compared with histopathological report. RESULTS The authors find that the calibration gives ρ(e) with an accuracy of ±3.5% while Z(eff) is found within ±1% of the actual value, the confidence being 95%. The HU(100) and HU(140) are found to be considerably different for the same plaque at the same position and there is a linear trend between these two HU values. It is noted that pure lipid type plaques are practically nonexistent, and microcalcification, as observed in histopathology, has to be taken into account to explain the nature of the observed (ρ(e), Z(eff)) data. This also enables us to judge the composition of the plaque in terms of basic model which considers the plaque to be composed of fibres, lipids, and microcalcification. CONCLUSIONS This simple and reliable method has the potential as an effective modality to investigate the composition of noncalcified coronary artery plaques and thus help in their characterization. In this inversion method, (ρ(e), Z(eff)) of the scanned sample can be found by eliminating the effects of the CT machine and also by ensuring that the determination of the two unknowns (ρ(e), Ze(ff)) does not interfere with each other and the nature of the plaque can be identified in terms of a three component model.

Airway obstruction after extubation following use of transesophageal echocardiography for posterior fossa surgery in the sitting position.

We report respiratory obstruction following surgery in the sitting position with tracheal intubation and placement of a transesophageal echocardiography probe. Obstruction was due to pharyngeal oedema, which resolved with 24 hours. The mechanisms of this complication are discussed.

Primary plasma cell granuloma of petrous bone

Plasma cell granulomas are rare intracranial lesions that can mimic a variety of intracranial tumours. As they are usually benign lesions, their identification assumes importance. We report a case of plasma cell granuloma in a 52-year-old man presenting with features of left sided V, VII and bilateral VIII nerve involvement who underwent subtotal excision of the lesion. The relevant literature is reviewed.

Accidental cut-throat injuries from the broken windshield of an auto rickshaw: Two unusual cases

Accidental cut-throat injuries are extremely rare and usually involve a sharp-edged weapon. In this paper, two cases of a cut-throat wound to two auto-rickshaw drivers are presented where the broken windshield of the auto-rickshaws was responsible for the wounds. In both the cases, fatal incised wounds were present over the neck, cutting the soft tissue along with the major vessels. The death occurred due to exsanguination caused by neck-vessel injury in one case and trachea along with neck-vessel injury in the second case. Although the wounds on the neck initially suggested homicide, they were found to have occurred accidentally as a result of a road traffic accident involving a head-on collision of auto rickshaws. The injuries were inflicted by the shattered glass of the windshield.