Standardisation of neurophysiological norm values. Relevance of the position of the heating element and the temperature measurement sensor

At a "constant" temperature of 37 degrees C, we measured the influence of the position of the temperature measurement sensor and the infrared heating element on the nervous conduction velocity (NCV) and the delay in latency after paired stimulation (LPSS) of the sural nerve. Temperature differences of up to 6.2 degrees C resulted from alteration of four cm in position of the temperature measurement sensor and the infrared heating element. NCV in the test subjects changed from 54.2 + -4.5 to 57.8 + -4.0 m/sec and the LPSS from 4.0 + -2.2% to 2.0 + -1.0%. The patients showed an increase of NCV from 54.1 + -5.0 to 56.8 + -5.7 m/sec and a decrease of LPSS from 9.9 + -5.7% to 6.5 + -3.9%. Our investigation shows that even the position of the temperature measurement sensor and the infrared heating element form a very appreciable component of the standardization method and decide on normal values. The consistent implementation of these results for routine purposes restricts the range of error of neurophysiological measurements, as well as improving the reproducibility and relevance of borderline findings.

Single photon emission computed tomography (SPECT) with 99mTc-HMPAO (hexamethyl propylenamino oxime) in chronic paroxysmal hemicrania--a case report

The case of a 69-year-old woman with chronic paroxysmal hemicrania (CPH) is presented in whom cerebral perfusion was investigated using the flow tracer 99mTc-hexamethyl propylenamino oxime (HMPAO) and single photon emission tomography (SPECT). There was a bilateral hypoperfusion in the fronto-parietal region between attacks--without medication as well as under effective treatment with verapamil. During an attack, however, SPECT investigation showed a normal cerebral perfusion. Further investigation is required to find out whether these SPECT findings are due to primary alterations of brain perfusion in CPH or are only of epiphenomenological nature. The observed effectiveness of verapamil in the prophylactic treatment of CPH should be verified in a greater number of patients.

Acetylsalicylic acid vs. metoprolol in migraine prophylaxis--a double-blind cross-over study

In a double blind cross-over study, 28 patients, 5 male and 23 female, aged 31 +/- 14 years, after a run-in period of 8 weeks, were treated for 3 months with acetylsalicylic acid and for another 3 months with metoprolol, both in a prophylactic mode. Attack frequency was reduced significantly with both therapeutic regimens (ASA p less than 0.001, metoprolol p less than 0.00005). Reduction of attacks below 50% was seen with metoprolol in 14 cases, and with ASA in three cases. Even though ASA was of statistically significant efficacy in migraine prophylaxis, it clearly is not the drug of first choice in migraine prophylaxis.

Brainstem auditory evoked potentials in migraine--evidence of increased side differences during the pain-free interval

Brainstem auditory evoked potentials (BAEPs) were recorded in 38 unselected patients (6 m./32 f.; age 18-54 yrs.) with various forms of migraine, during the pain-free interval. The values were compared to those of 50 control persons (18 m./32 f.; age 17-75 yrs.). Peak latencies (PL I-VI), interpeak latencies (IPL I-III, III-V, I-V) and side differences of all peaks (delta I-VI) were calculated. In contrast to PL's of migraine patients, all PL's of control persons were normally distributed. In 6 migraine patients (2 with basilar migraine) PL's were pathologically delayed. Statistical analysis did not show any significant difference in regard to PL's and IPL's between migraine patients and controls. However, side differences of all peaks (except peak IV,VI) were significantly increased in migraine patients as compared to controls. Our results indicate a slight but permanent impairment of brainstem function in migraine.

Single photon emission computed tomography with technetium-99m hexamethyl propylenamino oxime in the pain-free interval of migraine and cluster headache

Thirty-three headache-free patients (19 F/14 M) suffering from common (n = 9) and classic migraine (n = 19) as well as cluster headache (n = 5) were investigated using the flow tracer 99mTc-hexamethyl propylenamino oxime and single photon emmission computed tomography. A regional decrease of cerebral tracer uptake was observed in 16 patients with common migraine, but only in 3 patients with classic migraine and in no patient with cluster headache. In 10 of 15 cases with hemiplegic symptoms during migraine attack the areas of decreased tracer uptake showed a topographic relationship to neurological deficits. It appears that migraine attacks occur in connection with exacerbations of preexisting changes of neuronal activities, cerebral perfusion and metabolism.

Electronystagmographic investigations in migraine and cluster headache during the pain-free interval

An involvement of vestibulocochlear functions has been assumed to occur in migraine even in headache-free intervals. To obtain further information on this subject, we investigated an unselected group of patients with various forms of migraine (n = 94) and cluster headache (n = 8) during pain-free periods by means of electronystagmography (ENG). The investigation showed a normal ENG in all patients with cluster headache and in 85 (90.4%) patients with migraine. Five patients showed increased occurrence of horizontal deviations, indicating an impairment of vigilance. A pathological ENG was observed in only four patients, of whom one with "basilar migraine" showed a disturbance of central vestibular functions. Based on the employed methods, it is concluded that vestibular dysfunctions, and in particular those of central origin, are not common in cluster headache and in migraine-with the possible exception of basilar artery migraine.

[Neurocutaneous melanosis]

The authors report on a patient of 33 years of age suffering from neurocutaneous melanosis in whom two years after excision of a naevus pigmentosus et pilosus giganteus cellular proliferation of the melanoblasts in the area of the soft meninges was seen. This process led to the death of the patient within a few weeks' time despite intensive therapeutic measures, the manifestation being that of a generalised space-occupying growth in the CNS. Neuroradiological techniques can objectify the clinical pattern of signs of this very rare disease and may possibly enable an early diagnosis.

Brain imaging with 123I-IMP-SPECT in migraine between attacks

123I-IMP-SPECT brain imaging was performed in patients with classic migraine (n = 5) and migraine accompagnée (n = 18) during the headache-free interval. A regional reduction of tracer uptake into brain was observed in all patients with migraine accompagnée, while in patients with classic migraine only one case showed an area of decreased activity. The most marked alteration was found in a patient with persisting neurological symptoms ("complicated migraine"). In most cases the areas of decreased tracer uptake corresponded to headache localization as well as to topography of neurologic symptoms during migraine attacks. It may be concluded that migraine attacks occur in connection with exacerbations of preexisting changes of cerebral autoregulation due to endogenous or exogenous factors.

Paired stimulation and functional change of the sural nerve during beta blocker therapy

29 patients were examined during a therapy with beta blockers. The medication was applied over 12 weeks, 16 patients received propranolol 120 mg/day, 13 patients metoprolol 200 mg/day. Two patients showed side-effects. Neurophysiological examinations, i.e. sural nerve conduction velocity and paired stimulation of the sural nerve, revealed a slight decrease of nerve conduction velocity and a significant increase of the latency prolongation of the second nerve action potential when the medication was finished. These functional changes in the sural nerve may result from the interaction of metoprolol and propranolol with beta-receptors of the peripheral nerve.

Paraneoplastic subacute cerebellar degeneration in Hodgkin's disease. Report of three cases and review of the literature

12 cases of paraneoplastic cerebellar degeneration with Hodgkin's disease have so far been reported. Three additional patients (Stage II-IA/IIA/IIIB) are presented. Although CT and MR-imaging (MRI) revealed a marked cortical atrophy of the cerebellum, there was no evidence of direct brain involvement. After irradiation and chemotherapy all patients showed a complete remission. There was no evidence of primary disease after an observation period of 3/2/5 years. Cerebellar symptoms also showed a partial remission. As compared to the literature, our treatment appears to be more favorable, probably due to the fact, that therapy was more aggressive than usual.

[Dysfunction of the sural nerve in cigarette smokers]

Sural nerve conduction velocity (NCV) and relative refractory period (RRP) using paired stimuli was performed on 34 healthy smokers and on 34 healthy non-smokers. No smoking probands showed a NCV of 52.2 +/- 4.1 m/sec, the smoking probands 50.7 +/- 4.1 m/sec. The RRP of the first group was 2.6 +/- 1.3%. On contrast to these results the RRP of smoking probands was 5.8 +/- 1.5%. The differences of the RRP between smokers and non-smokers are significant (p less than 0.001 Wilcoxon-test). In order to investigate the persistence of this functional impairment of the sural nerve, 19 healthy probands, who had stopped smoking (R = 0.25-13 years), were examined also. The NCV of this group was 52.2 +/- 4.5 m/sec and the RRP 3.9 +/- 1.9%. The RRP of ex-smokers is different from smoking and non smoking probands (Wilcoxon-test, p less than 0.05). The results of our investigation clearly demonstrate, that smoking induces a slight dysfunction of the sural nerve, which is not completely reversible. This may suggest, that smoking induces for example subclinical changes of the myelin sheath. In general, healthy probands are not asked for their smoking habits. It may be concluded that smoking represents an important and problematical factor concerning the age-dependency of peripheral nerve function.

Chronic ergotamine abuse: evidence of functional impairment of long ascending spinal tracts

22 migraine patients with a history of chronic ergotamine abuse were compared with 12 patients with a similar intake of dihydroergotamine. The study of somatosensory-evoked potentials showed that 50% of the patients with a history of ergotamine abuse had increased central conduction times after stimulation of the tibial nerve. Corticomotoneuronal latencies obtained by noninvasive electrical stimulation of the motor cortex were normal in 5 patients. The functional sensory deficits were not related to clinical impairment and were more frequently observed in patients with a comparatively high mean daily and cumulative intake.

[Betablocker vs placebo in vasomotor headache. A double-blind crossover study]

Vasomotor headaches are commonly, especially in the international literature, classified under ordinary migraine. Since beta-blockers seem to be the drug of choice in the prevention of migraine, 30 patients were given placebo and three times 40 mg propranolol in a double-blind cross-over trial. Among 24 fully assessable sets of tests only four showed a decrease in the frequency of headaches by more than 50%. In three patients the frequency actually increased over the placebo effect.

123I-amphetamine-SPECT in classical migraine and migraine accompagnée

Migraine is considered to be a functional neurological disorder. In classical migraine (headache associated with prodromal visual field disturbances) and migraine accompagnée (headache associated with transient neurological symptoms), disturbances of cerebral blood flow and amine metabolism are thought to be pathogenetic factors. However, conventional methods of neuroimaging (CAT, NMR) usually do not yield any pathological findings in patients. Since 123I-iodoamphetamine (123I-IMP) crosses the intact blood brain barrier, 123I-IMP-SPECT is used for the assessment of cerebral perfusion in various neurological diseases, including functional disorders. 123I-IMP-SPECT was performed on 5 patients with classical migraine and 18 patients with migraine accompagnée. At the time of investigation, all patients were symptom-free. Cerebral blood flow was decreased in all patients with migraine accompagnée, and often corresponded to the site of headache as well as to the topography of transient neurological symptoms. This reduction was most obvious in a patient with persisting neurological symptoms. Most patients with classical migraine, however, did not show any alteration of cerebral perfusion. It appears that migraine--and in particular migraine accompagnée--is characterized by a permanent alteration not only of cerebral blood flow but also of neuronal activity. Migraine attacks may occur in connection with exacerbations of preexisting metabolic alterations.