Clinical evaluation of the driving ability in stroke patients

OBJECTIVES

Stroke often causes physical, cognitive and psychomotor dysfunction, which markedly decreases the driving ability of stroke patients. The aim of this study was to evaluate the driving ability of stroke patients using multidisciplinary clinical evaluation and driving-related laboratory tests.

MATERIALS AND METHODS

A neurologist evaluated the driving ability of 20 male stroke patients on the basis of his own clinical examination and the observations and measurements of a neurological multidisciplinary rehabilitation team. After that a traffic psychologist evaluated the patients' driving ability on the basis of the driving-related cognitive and psychomotor laboratory tests. The patients themselves also evaluated their driving ability, as did their spouses. All the evaluations were carried out independently using the same 10-point scale. The control group consisted of 20 healthy males, matched by age and driving experience, who went through the same laboratory test package as the patients did.

RESULTS

The stroke patients had more deficiencies in all tested driving related cognitive and psychomotor functions than the controls. The neurologist and the psychologist together evaluated 12 (60%) of the 20 stroke patients being unable to drive; 8 patients out of 11 with non-dominant hemisphere lesion and 4 in the dominant group. The patients themselves and their spouses had a clear tendency to overestimate driving ability compared to the estimates of the neurologist and the psychologist. The hit-rate of the evaluations of the neurologist and traffic psychologist (75%) was high.

CONCLUSION

Stroke patients form a risk group as drivers due to their decreased cognitive and psychomotor abilities, and driving ability should always be evaluated after stroke. The results suggest that multidisciplinary neurological teams are able to evaluate the driving ability of stroke patients reliably. A careful evaluation of driving ability without a driving test requires assessment of cognitive and psychomotor functions critical in driving, which is not feasible for physicians without the support of a multidisciplinary team and/or traffic-related laboratory tests.

Decreased driving ability in people with Parkinson's disease

BACKGROUND

Driving is a complex form of activity involving especially cognitive and psychomotor functions. These functions may be impaired by Parkinson's disease. The relation between Parkinson's disease and driving ability is still obscure and clinicians have to make decisions concerning the driving ability of their patients based on insufficient information. Until now no studies have compared different methods for evaluating the driving ability of patients with Parkinson's disease.

METHODS

The driving ability of 20 patients with idiopathic Parkinson's disease and 20 age and sex matched healthy control subjects was evaluated by a neurologist, psychologist, vocational rehabilitation counsellor, and driving instructor using a standard 10 point scale. The patients and controls also evaluated their own driving ability. Cognitive and psychomotor laboratory tests and a structured on road driving test were used for evaluating the subjects' driving ability.

RESULTS

The patients with Parkinson's disease performed worse than the controls both in the laboratory tests and in the driving test. There was a high correlation between the laboratory tests and driving test both in the patient group and in the control group. Disease indices were not associated with the driving test. The neurologist overestimated the ability of patients with Parkinson's disease to drive compared with the driving ability evaluated by the structured on road driving test and with the driving related laboratory tests. Patients themselves were not capable of evaluating their own ability reliably.

CONCLUSION

Driving ability is greatly decreased in patients with even mild to moderate Parkinson's disease. The evaluation of patients' driving ability is very difficult to carry out without psychological and psychomotor tests and/or a driving test.

Early neuropsychological outcome after carotid endarterectomy

30 patients with a history of transient ischemic attacks (TIA) and 16 patients with cerebral infarcts were evaluated neuropsychologically 1-3 days before carotid endarterectomy, due to hemodynamically significant carotid artery stenosis, and again 2 weeks and 2 months after operation. Preoperatively, there were no differences between the groups, but postoperatively the neuropsychological outcome of the TIA patients was better than that of the infarction patients. Consequently, carotid endarterectomy patients cannot be studied as one group in neuropsychological examinations but various subgroups should be dealt with separately. In the TIA group 2 months after operation, the patients with left-sided operations had improved in verbal but not in visual tests, and the right-operated patients showed improvement also in visual tests. Therefore, the use of sum scores across neuropsychological tests is not preferable in the evaluation of the effects of carotid endarterectomy because after unilateral operation the cognitive improvement is greater in functions ipsilateral to the operation side.

Spontaneous dissection of the internal carotid artery

Spontaneous dissection of the internal carotid artery is not well known in Scandinavia. Several hundred cases have been reported world-wide, but none from Finland. We presume the annual incidence in Finland to be at least 20-30 cases, nearly all of which remain undiagnosed. Our experience of 12 cases indicates that the typical patient is a middle-aged man who after strenuous physical exertion suffers a transient ischemic attack or progressing stroke. Manifestations may include ipsilateral incomplete Horner's syndrome and facial or cervical pain. The diagnosis is based on angiography and verified from repeat angiograms. The most typical finding is an extracranial stenosis or occlusion of the internal carotid artery. Irregular expansion, double lumen and aneurysmal dilation are also fairly common. The stenotic area usually recanalizes in a few months. Nonsurgical management is recommended. Prompt diagnosis and adequate heparinization with simultaneous start of oral anticoagulation seem to give the best final result.

Botulism revisited. A case report

Two cases of food-borne botulism following consumption of commercially canned German-made liver sausage are presented. The more serious case involved respiratory paralysis for 15 days, the milder one only muscle weakness in the area of the cranial nerves. Both of the patients recovered well and returned to their jobs half a year after the onset of the illness.

Neurological findings in patients with pseudopapilloedema with and without verified optic disc drusen

As part of a clinical examination of 200 patients with pseudopapilloedema with and without verified optic disc drusen, neuroophthalmological examinations were performed in 158, neurological examinations in 117 and electroencephalography in 109 patients. Headache and suspected papilloedema were the most frequent reasons for referral. Headache was one of the complaints in 102 patients. Migraine was diagnosed in 22 and suspected in 3 patients. Epilepsy was present in 9 patients and in addition, 1 patient had had treatment for convulsions in childhood. 2 patients had a pituitary tumour and 1 had a tumour in the hypothalamic region. Various other neurological disorders appeared in small numbers. Abnormalities in electroencephalograms (EEGs) were found in 36 patients. Progressive loss of central visual acuity unexplained by retinal pathology as well as bitemporal and homonymous hemianopic visual field defects and also evidence of papilloedema warrant a neurological examination in patients with optic disc drusen.

Elimination of extracranial blood flow during dynamic cerebral perfusion studies using diffusible and non-diffusible radioisotope

The extracranial blood flow seriously complicates the interpretation of dynamic cerebral studies. To eliminate this, we used a blood pressure cuff placed around the head in 50 patients with no evidence of cerebrovascular disease. The pressure in the headband was increased to 30 mmHg above the patient's systolic pressure, and the first 60 sec static scintigram was taken exactly 3 min after the injection of 99mTc-pertechnetate. A second 60 sec static scintigram was taken without pressure in the headband at 6 min after injection. After correction for diffusion of tracer into extravascular compartments we could still show 13% reduction in counting rates over the hemispheric regions and 30% over the convexity regions during application of the pressure headband. With the Xenon method, the application of the headband appears to have insignificant influence on the results of cerebral perfusion. We thus recommend that a headband should be used for dynamic 99mTc-isotope cerebral circulation studies.

Non-invasive external regional measurement of cerebral circulation time changes in supratentorial infarctions using pertechnetate

A method for measuring regional cerebral circulation time (rCCT) between the hemispheres using intravenous pertechnetate and a multidetector system is presented. Interhemispheric differences of rCCT instead of absolute values were selected because of the variation of pertechnetate bolus dispersion due to changes in the systemic circulation and injection technique inter-and intraindividually. Time activity curves over one minute were analyzed by a modified gamma function fitting method. The results are printed as a brain map which shows reference values and abnormal findings. Abnormal rCCT asymmetry was observed in 10 out of 77 controls (13%) and 58 out of 65 patients with cerebral infarction (89%). Within 2 weeks after a stroke shorter circulation time values on the side of the lesion than on the contralateral side were found in 5 patients. In the severe infarction cases and in the acute stages of infarction circulatory changes could be found in a great number of areas. In patients with manifest diabetes abnormal circulatory findings occurred in larger regions and in a greater number of the patients than in those without that disease. Although the luxury perfusion and diaschisis phenomena, as well as the influence of cross-over of the count rates between the hemispheres, reduce circulatory time differences, use of the present pertechnetate method allows detection of subtle regional circulatory changes in patients with brain infarction.

Serial measurements of quantitative EEG and cerebral blood flow and circulation time after brain infarction

The quantitative EEG (QEEG), regional cerebral blood flow (rCBF) and circulation time of 17 patients were examined semisimultaneously thrice during the first 3 months after a cerebral supratentorial infarction. The EEG was quantified according to normalized slope descriptor technique in nine patients and by means of a combined period and amplitude analysis in eight patients. Intravenously injected isotopes 133Xenon and 99TcmO4 were used for blood flow and circulation time measurements. The QEEG-values improved during the whole follow-up period. Cerebral blood flow stayed low for all 3 months and did not alter during this period, while initially prolonged circulation time to some extent improved within 2 weeks remaining, however, prolonged even thereafter. A tendency for a positive correlation between QEEG and rCBF values in the infarcted hemisphere could be seen.

Electroretinogram (ERG) and visual evoked response (VER) studies in patients with optic disc drusen

Non-corneal ERGs, recorded from infraorbital skin electrodes to flash stimulation and mid-occipital and parasagittal VERs to both flash stimulation and pattern reversal were performed in 26 patients with optic disc drusen. ERGs were normal in all patients. The mean VER amplitude was lower in the eyes with optic disc drusen than the mean amplitude of VERs in the normals but the interindividual variation was also so great in normals that the difference was not significant. The waveform of the major positive peak was quite often broad or split. VER latencies were usually in normal range although the visual field defects could be rather severe. Some other cause was present when the major positive peak was delayed.

Evaluation of cerebral infarctions of the carotid area by an intravenous 133Xenon and 99mTechnetium method

Quantitative determinations of regional cerebral blood flow (rCBFf, rCBFm) and volume (rCBV), transfer time (rCTT) and fast compartmental weight (Wf) were performed in 34 patients with infarctions of the carotid area by a 133Xe and 99mTc intravenous injection method. The results were compared with clinical signs and electroencephalographic (EEG) findings. A significant difference was found between the lesion side and the control side in all the parameters except rCBV. This difference increased with the severity of the infarction and age of the patients. The difference between the two sides was especially great in the patients with totally occluded internal carotid artery. A slight diaschisis could be observed in the present infarction group. An almost significant reduction on the "normal side" was seen in Wf. In order to assess the reciprocal influence of all the different blood flow parameters, the difference index (DI): Formula: (see text) was calculated, where delta i = the difference between the two sides in one parameter expressed in percent. This proved to be abnormal in 80% of the patients. The atraumatic isotope technique employed offers a good opportunity for the quantitative evaluation of hemodynamics in cerebral infarction and serves as an aid in the diagnosis of infarction.

An intravenous isotope method for measuring regional cerebral blood flow (rCBF) and volume (rCBV)

The regional cerebral blood flow (rCBF), intial slope index (ISI), transfer time (th) and volume (rCBV) were measured simultaneously in 43 hospital patients using a 133Xe intravenous injection method and quantitative dynamic 99Tcm brain scintigraphy. The measurements were made with a gamma camera and the data processing interfaced with a small digital computer. The following mean values and standard deviations were obtained from 50 control hemispheres standardized to the age of 40 years: (formular): see article. Good agreement was found between the blood flow values determined from the intra-arterial and intravenous injection techniques.