Continuous-pressure controlled, external ventricular drainage for treatment of acute hydrocephalus--evaluation of risk factors.

Experience with a continuous-pressure controlled, external ventricular drainage system (EVD) in 100 patients (n = 49 female, n = 51 male; mean age, 56.3 yr) with acute hydrocephalus is reported. Cerebrospinal fluid circulation disturbances resulted from hemorrhages caused by subarachnoid hemorrhage (n = 45), parenchymal hemorrhages from angioma (n = 4), anticoagulants (n = 7), or hypertension or other reasons (n = 30); in addition, hydrocephalus developed from infections (n = 3), tumors (n = 2), infratentorial infarction (n = 5), or unknown reasons (n = 4); 52 patients had ventricular hemorrhages. No patient died of system-associated morbidity. Mean time of EVD treatment was 9.5 days, with 40 patients being treated for 10 to 29 days; routine refobacin (5 mg) flushing of the system was performed three times a day. Patients without cerebrospinal fluid leakage had a 2% rate of secondary infection compared with 13% in patients with cerebrospinal fluid leakage due to ventricular catheter placement (P < 0.05; overall infection rate, 5%). A clinical mortality rate of 29% during EVD treatment was observed in subarachnoid hemorrhage patients (Hunt and Hess Grades II, III, IV, and V; n = 9, 9, 18, and 9, respectively); recurrent hemorrhages during EVD treatment occurred in 19 patients (26 hemorrhages), and of these, 10 patients died. System occlusion was seen in 19 cases (12 of 45 patients with subarachnoid hemorrhage), requiring catheter and system renewal in 1 case; system extraction was seen in 3 cases, misplacement was seen in 11 cases, and disconnection was seen in 5 cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of motor unit firing rates by standard concentric needle electromyography.

Motor unit firing rates at slight voluntary contraction were studied by standard concentric needle electromyography. Employing digital signal analysis techniques firing rates of motor units (MU) could be evaluated as long as four or less different MUs were activated in the vicinity of the concentric needle electrode. The extension of the recording area is defined by the recording properties of the electrode and the upper limit of rise-time for all MUPs being evaluated. Distant MUs, generating volume conducted potentials with rise-times greater than 0.8 ms, were excluded. In biceps muscles of 15 healthy controls the firing rate of the MU activated first was evaluated at that moment, when a second MU was recruited and was found to be 12.1 +/- 2.1 Hz (mean +/- S.D., n = 40). The firing rate of the fastest MU out of 2, 3, or 4 simultaneously active MUs was 10.7 +/- 2.5 Hz, 10.9 +/- 2.5 Hz and 10.6 +/- 2.4 Hz respectively. Hence at low innervation level there is no increase of firing rate with rising number of activated MUs. The upper normal limit of MU firing rate (3 sigma interval) is calculated as 17 Hz, irrespective whether 1, 2, 3 or 4 MUs are active within the recording area. Fifteen patients with partially denervated biceps muscles were investigated. Maximal firing rates were increased in 10 patients, all showing moderate or severe paresis (grade 1-3). In 10 patients suffering from myopathies firing rates always were normal. The presented data may serve as an additional criterion in evaluating MU firing rates during standard clinical EMG.

Real-time sonography of acute and chronic muscle denervation.

Presented are real-time ultrasound findings in partially and completely denervated muscles of 30 patients with focal neuropathy and various other disorders of the second motor neuron. Sonographic scans of affected muscles are analyzed in conjunction with unaffected muscles of the same individual, under identical examination conditions. Initial pathological ultrasound changes could be detected as soon as 2 weeks after an acute neurogenic lesion. In denervation, the echodensity of the muscle was high and the normal intramuscular pattern was decomposed. Findings were more intense in severe and longstanding denervation. Ultrasound-indicated pathology correlated highly (chi-square: P less than 0.001) with pathological spontaneous activity detected by electromyography. Focal and systemic neuropathies showed no differences in ultrasound pathology. Six cases with central motor palsy had normal sonograms. Poor spatial resolution of real-time ultrasonography--as compared with CT and MRI--is compensated by its bedside availability, frequent repeatability without patient risk and discomfort, and its in vivo correlation of muscle morphology with muscle function.

[Severe late-onset dystonia while on fluspirilene]. / Schwere Spätdystonie unter Fluspirilen.

Shooting, tonic cramps of the neck muscles with jolt-like contractions in the mouth and jaw regions and propulsive movements of both arms developed in a 25-year-old woman who, over a period of six months, had been given nine intramuscular injections of the depot neuroleptic fluspirilene, 1.5 mg each, because of apathy and depression. Treatment with biperiden (up to 20 mg daily) and benzodiazepines was unsuccessful, while tiapride (up to 1000 mg daily) brought about slight improvement and 15 mg haloperidol achieved complete remission. However, distinct parkinsonian features developed. Slow gradual reduction of the haloperidol dose again led to extrapyramidal motor symptoms, even when tiapride or bromocriptine was given as well. After six months' administration of clozapine, up to 500 mg daily, and gradual dose reduction all symptoms fully regressed. This case demonstrates that the risk of extrapyramidal motor abnormalities from "neuroleptic anxiolysis" should not be underestimated.

[Unit potential analysis in the diagnosis of myopathies: development of quantitative EMG parameters]. / Einzelpotentialanalyse in der Myopathiediagnostik: Entwicklung quantitativer EMG-Parameter.

In standard concentric needle electromyography the typical triphasic potential of a motor unit (MUP) consists of the spike component and the positive initial and terminal parts. Whereas the main spike is generated by a few muscle fibers located close to the tip of an electrode, the initial and terminal parts represent the sum of activities of a large proportion of fibers within the motor unit. The size of the initial and terminal part is assessed by measuring the duration of the MUP. In addition to the duration we calculated the mean absolute voltage outside the spike component: The signal was digitized and several individual MUPs of the same motor unit were averaged. The point of maximal negative rise was identified. Then the mean absolute voltage between -5 ms and +5 ms around this point, excluding the interval from -1 ms to +1 ms, was calculated. This parameter is exactly defined and unambiguous. The biceps brachii muscles of 30 healthy volunteers were examined in order to establish normal values. In 24 patients suffering from various myopathies 18 had significant (p less than 0.01) reduced initial and terminal parts, whereas only 13 patients showed decreased potential duration (according to Buchthal 1957).