The investigation of acute severe headache suggestive of probable subarachnoid haemorrhage: a hospital-based study

Thunderclap headache as a first manifestation of acute disseminated encephalomyelitis: case report and literature review

BACKGROUND

Acute Disseminated Encephalomyelitis (ADEM) is an acute demyelinating disorder of the central nervous system, characterize by multiple white matter hyperintensities on T2 MRI. Patients usually present with subacute progressive encephalopathy and polyfocal neurological deficits. Possible treatments are corticosteroids, immunoglobulins and plasma exchange. Full clinical recovery is seen in more than half of the cases.

CASE

We describe a case of a 62-year-old patient presenting with thunderclap headache as the first symptom, two weeks after an upper respiratory tract infection. The clinical course was complicated by progressive coma and intracranial hypertension mandating external ventricular drainage and sedation. Initial treatment with methylprednisolone was unsuccessful but clinical resolution and radiological regression was achieved after plasma exchanges and cyclophosphamide.

CONCLUSION

To our knowledge, this is the first reported case of ADEM presenting with thunderclap headache. Intracranial hypertension with the need for invasive neuromonitoring and pressure management is also a very rare complication of ADEM. In this report, we describe the findings of the literature review concerning ADEM, thunderclap headache and intracranial hypertension.

Role of computed tomography before lumbar puncture: a survey of clinical practice

INTRODUCTION

It is becoming increasingly common to request computed tomography (CT) to rule out space occupying lesions before lumbar puncture (LP), even in patients with no clinical signs. Imaging trends within a busy district general hospital in Oxfordshire, UK were analysed with results used to clarify when imaging should be considered mandatory.

METHOD

A retrospective six month sample was obtained comprising all adults considered for LP. Observed frequencies of abnormal examination findings compared with abnormal investigations were used to determine sensitivity, specificity, positive predictive, and negative predictive values to assess the validity of using a normal clinical examination as a basis for excluding CT.

RESULTS

64 patients were considered for LP. In total, 58 patients underwent LP, with a single patient receiving two. After an abnormal CT scan, six patients did not undergo a planned LP. In all six of these cases subarachnoid haemorrhage was detected, and in all cases this was considered a probable diagnosis. In no case was an LP precluded by an unsuspected space occupying lesion. Neurological examination showed a sensitivity of 0.72 (0.52 to 0.93), specificity 0.78 (0.64 to 0.91), positive predictive value 0.61 (0.41 to 0.83), and negative predictive value 0.85 (0.73 to 0.97).

DISCUSSION

The high sensitivity and negative predictive values support normal neurological examination as an effective predictor of normal CT scan. This permits the recommendation in cases where subarachnoid haemorrhage is not suspected, a CT scan can be avoided provided there are no abnormal findings on physical or fundoscopic examination.