The impact of ergotamine-induced headache and ergotamine withdrawal on information processing

Ergotamine abuse and subsequent ergotamine-induced headache is a common problem in the pharmacological treatment of migraine and other headache types; often, withdrawal therapy is necessary. This study investigated whether ergotamine abuse affects information processing and whether withdrawal therapy can lead to an improvement of information processing. We designed a standardized neurophysiological retrospective (ergotamine abuse) and prospective (ergotamine withdrawal) study in a supraregional headache outpatient clinic. Seventy-one patients abusing ergotamine derivatives with subsequent daily headache were enrolled and compared to 36 migraine patients without ergotamine intake and 36 healthy subjects. Information processing was evaluated by latencies and amplitudes of visually evoked event-related potentials (ERP) before and after ergotamine withdrawal therapy. P3 latency of the ERP was significantly increased in ergotamine abuse (442 ± 45 ms) versus migraine (415 ± 40 ms) and healthy subjects (410 ± 33 ms), there was no difference between ergotamine tartrate and dihydroergotamine abuse. The migraine specific loss of habituation in information processing as measured by P3 latency could not be observed in migraine patients with ergotamine abuse. After successful withdrawal therapy in 36 patients, the abnormally prolonged P3 latency was significantly shortened (452 ± 47 ms versus 433 ± 30 ms; P < 0.004). Our findings imply that information processing is impaired by ergotamine abuse and can be improved but not normalized after withdrawal therapy. Furthermore, our data provide strong evidence that ergotamine, besides its peripheral effects, has a central mode of action. Received: 16 March 1998/Final version: 27 July 1998     

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.     

Cerebral vasculopathy in HIV infection revealed by transcranial Doppler: A pilot study

BACKGROUND AND PURPOSE: There is growing evidence for affection of cerebral vessels during human immunodeficiency virus (HIV) infection. We prospectively evaluated cerebrovascular reserve capacity (CRC) in HIV-seropositive patients by transcranial Doppler sonography (TCD) after systemic administration of acetazolamide. We hypothesized that a disturbed vasoreactivity would reflect the cerebral arteries' involvement in HIV infection. METHODS: We assessed the mean blood flow velocity (BFV) of the middle cerebral artery and its increase after intravenous administration of 1 g acetazolamide (CRC) in 31 HIV-infected individuals without symptoms of cerebrovascular disease (mean+/-SD age, 39+/-11 years). Stenotic or occlusive lesions of the large brain-supplying arteries were excluded by color-coded duplex and transcranial imaging. BFV and CRC were also measured in an age-matched group of 10 healthy control subjects. Patients were classified according to clinical, laboratory, and neurophysiological parameters. We also performed cerebral MRI (n=25) and rheumatological blood tests (n=26). RESULTS: Baseline BFV and CRC both were significantly reduced in HIV-infected patients as compared with control subjects (P<0.05, Student's t test). These findings did not correlate with duration of seropositivity, helper cell count, or other clinical, rheumatological, and neuroradiological findings. CONCLUSIONS: Our findings support the hypothesis of a cerebral vasculopathy etiologically associated with HIV infection.     

Cidofovir in combination with HAART and survival in AIDS-associated progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy is a demyelinating disease with a high mortality caused by the JC virus and occurs in about 5% of HIV-infected patients. Highly active anti-retroviral therapy (HAART) has a proven efficacy in prolonging the survival of patients with AIDS-associated PML, but there are differing opinions about adding cidofovir to the treatment of PML. To investigate the benefit of HAART combined with cidofovir, we retrospectively analysed the survival of 33 patients with AIDS-associated PML proven by PCR in CSF, biopsy or at autopsy. Additionally, we also analysed 37 patients with probable PML. Seventeen (51.5%) of the patients with confirmed PML were treated with HAART and 14 (42.4%) with cidofovir in any combination. Of these patients, 13 (39.4%) were treated with HAART and cidofovir in combination, four (12.1%) patients received only HAART without cidofovir and one (3%) patient received only cidofovir without HAART. Fifteen patients did not receive HAART or cidofovir. The cumulative survival was significantly longer in patients with HAART than in patients without HAART (p = 0.006), independent whether cidofovir was given or not. In comparison with single therapy with HAART, the combination of HAART and cidofovir showed no significant increase in survival (p = 0.435). Therefore, a benefit for cidofovir in addition to HAART in the treatment of PML in HIV-infected patients could not be proven.     

Prevention of AIDS dementia by HAART does not depend on cerebrospinal fluid drug penetrance

The impact of the cerebrospinal fluid (CSF) penetrance properties of different highly active antiretroviral therapy (HAART) regimes on cognitive processing in AIDS dementia is still undetermined. We therefore designed a retrospective cross-sectional and prospective longitudinal analysis of event-related potentials in HIV-infected patients with different combinations of HAART or without antiretroviral treatment. A total of 353 consecutive patients without secondary CNS manifestation of HIV infection were enrolled in the cross-sectional study and 135 consecutive patients without secondary CNS manifestations of HIV infection were enrolled in the longitudinal study. HAART in different combinations (n = 306) or no antiretroviral treatment (n = 47) was given for at least 6 months in the retrospective cross-sectional study. HAART in different combinations (n = 110) or no antiretroviral treatment (n = 25) was given for 1 year in the prospective longitudinal study. We evaluated the latency and amplitude of the P3 component of visually evoked event-related potentials and mean choice reaction time as measures of cognitive processing. Patients receiving HAART had decreased P3 latencies as compared to those patients not receiving HAART but P3 latency and P3 amplitude were not correlated with the amount of CSF penetrance of the different HAART combinations in either statistical analysis. However, mean choice reaction time was significantly correlated with the amount of CSF penetrance. In HIV-infected patients, the CSF penetrance properties of HAART do not have any significant influence on cognitive processing as measured by event-related potentials.