Cerebellar strokes: a clinical outcome review of 79 cases

INTRODUCTION

Cerebellar infarcts and haemorrhages are relatively uncommon, accounting for less than 10% of all strokes. The objective of the present study was to quantify and compare the outcomes of patients with cerebellar infarct and those of patients with cerebellar haemorrhage, as well as to identify the risk factors that predict poor outcome in patients with cerebellar stroke.

METHODS

We retrospectively reviewed the medical records of consecutive patients admitted to National University Hospital, Singapore, between 2004 and 2006, within one week of cerebellar stroke onset. Baseline data included demographics, concomitant comorbidities, and the presence or absence of brainstem compression and hydrocephalus (on computed tomography or magnetic resonance imaging). The Glasgow Outcome Scale and modified Rankin Score were used to assess outcome at discharge and at six months after discharge.

RESULTS

A total of 79 patients with cerebellar stroke were admitted during the study period. Of these 79 patients, 17.7% died and 31.6% had poor outcomes at six months after discharge. Patients with cerebellar haemorrhage were found to be more likely to have poor outcomes as compared to patients with cerebellar infarct, both at discharge (odds ratio [OR] 4.3, 95% confidence interval [CI] 1.3-14.1) and at six months after discharge (OR 5.2, 95% CI 1.6-17.2). When compared to small lesions (< 5 cm(3)), lesions > 20 cm(3) were significantly associated with poorer outcomes and the development of hydrocephalus and brainstem compression.

CONCLUSION

Cerebellar strokes are a significant cause of morbidity and mortality. The outcomes of patients with cerebellar haemorrhage are more likely to be worse than those of patients with cerebellar infarct.

Effect of basic military training on hearing in the Singapore Armed Forces

INTRODUCTION

In the military service, hearing is at risk through exposure to impulse noise from firing and detonations. This study aims at looking into the consequences of military training on hearing acuity, as it would be useful to confirm the effectiveness of the hearing conservation programme in the Singapore Armed Forces.

METHODS

A self-controlled study of 118 Singapore military conscripts was carried out, using questionnaires administered by trained personnel and pure tone audiometric assessments performed for both ears. The questionnaire and audiometry were done at the start of basic military training (BMT), with follow-up audiometry done at the end of BMT and one year into vocational military training (VT).

RESULTS

33 military conscripts were excluded subsequently in latter phases of the study. Of the 85 remaining conscripts, 16.5 percent of the study population were found to have abnormal audiograms at the start of BMT. At the end of the BMT phase, the percentage of enlistees with abnormal audiograms was 9.4 percent. By the end of one year of VT, the percentage of enlistees with abnormal audiograms was still 9.4 percent. Analysis of the differences in number of enlistees with hearing loss was done with the McNemar's test, and was found to be statistically insignificant (p-value equals 0.238).

CONCLUSION

The prevalence of 16.5 percent abnormal audiograms at the pre-BMT stage is probably related to unfamiliarity with the audiogram testing and/or "temporary threshold shift" effect. There was no significant difference in the number of enlistees with hearing loss upon enlistment and after one year of military training in this cohort of soldiers.

Postural stability and neurobehavioural effects of heat exhaustion among adult men

The medical complications of heat disorders, including haematological, cardiovascular and renal damage, have been well documented. However, very little has been written on its neurological complications. The objective of this study was to assess the effects of heat exhaustion on postural stability and neurobehavioral functions of men. The study is prospective in design and spans a 3-year period. All soldiers who were diagnosed to have heat exhaustion (cases) from 1 March 1998 to 31 August 1998 were included in the study. For each case, a healthy soldier (matched for age, ethnicity, years of education and military vocation) was recruited to serve as control. Each subject had a neurobehavioral assessment by using the Swedish Performance Evaluation System (SPES), a computerized test battery. The postural stability of the subjects was assessed using a computerized postural sway system. Findings for 37 heat exhaustion cases and 37 controls revealed that cases had a significantly higher prevalence of neurasthenia symptoms compared to the controls. There were significant (small) differences between the cases and controls in the neurobehavioral tests of choice reaction time, digit span and some parts of colour word stress and logical series measures. Postural stability in the cases was significantly poorer when in the "eyes-closed" condition, compared with the controls. Men with heat exhaustion, studied 2 weeks after the acute episode, had significantly more symptoms of neurasthenia, poorer performance in short-term memory and slower reaction time. The cases (as a group) had significantly poorer postural stability.