[Damage of teres minor branch of axillary nerve]. / Kainalohermon teres minor -haaran vaurio hartiakivun yhteydessä.

Atrophy demarcating to musculus teres minor is seen in magnetic resonance imaging of the shoulder region in 3 to 5.5% of investigations. We describe seven patients with prolonged or recurrent pain of the shoulder region, who were diagnosed in ENMG with damage of the axillary nerve brand to m. teres minor. Probable causes included tear of the rotator cuff, luxation of the shoulder joint, nerve entrapment in the quadrilateral space, neuritis of the brachial plexus and iatrogenic damage associated with shoulder arthroscopy. This nerve damage cannot be proved clinically.

Cognitive and neurophysiological outcome of cardiac arrest survivors treated with therapeutic hypothermia.

BACKGROUND AND PURPOSE: Cognitive deficits are common in survivors of cardiac arrest (CA). The aim of this study was to examine the effect of therapeutic hypothermia after CA on cognitive functioning and neurophysiological outcome. METHODS: A cohort of 70 consecutive adult patients resuscitated from out-of-hospital ventricular fibrillation CA were randomly assigned to therapeutic hypothermia of 33 degrees C for 24 hours accomplished by external cooling or normothermia. Neuropsychological examination was performed to 45 of the 47 conscious survivors of CA (27 in hypothermia and 18 in normothermia group) 3 months after the incident. Quantitative electroencephalography (Q-EEG) and auditory P300 event-related potentials were studied on 42 patients at the same time point. RESULTS: There were no differences between the 2 treatment groups in demographic variables, depression, or delays related to the resuscitation. No differences were found in any of the cognitive functions between the 2 groups. 67% of patients in hypothermia and 44% patients in normothermia group were cognitively intact or had only very mild impairment. Severe cognitive deficits were found in 15% and 28% of patients, respectively. All Q-EEG parameters were better in the hypothermia-treated group, but the differences did not reach statistical significance. The amplitude of P300 potential was significantly higher in hypothermia-treated group. CONCLUSIONS: The use of therapeutic hypothermia was not associated with cognitive decline or neurophysiological deficits after out-of-hospital CA.

P300 of auditory event related potentials in occupational chronic solvent encephalopathy.

This retrospective study characterized the P300 component of the auditory event related potential (ERP) and assessed its diagnostic value in occupational chronic solvent encephalopathy (CSE). The P300 was recorded on 86 CSE patients by the classical oddball paradigm. In addition to the laboratory's reference values, we used an age and education matched control group that consisted of 104 blue-collar workers with no known occupational solvent exposure. The association of P300 values with solvent exposure indices, major depression, alcohol consumption, and neuropsychological parameters was studied. The P300 amplitude was lower in CSE patients (mean 7.5 microV; S.D. 3.6) compared to laboratory controls (mean 11.8 microV; S.D. 4.1; F(1,167)=24.4; p<0.001, 95% CI -4.4 to -1.8) and to matched controls (mean 9.0 microV; S.D. 4.0; p=0.007, 95% CI -2.6 to -0.4). The P300 latency was longer in the CSE patients (mean 358 ms; S.D. 28) compared to laboratory controls (mean 339 ms; S.D. 19, F(1,167)=7.6, p=0.006, 95% CI 3.12-18.7) but did not differ from matched controls (mean 358 ms; S.D. 22; p=0.947, 95% CI -7.4 to 6.9). The solvent exposure indices, major depression, or alcohol consumption did not associate with the P300 values. The P300 amplitude correlated positively with the Digit Symbol test. All the amplitude values in the patient group and in the matched control group were classified as normal (i.e. age corrected mean+/-2.5S.D.) against the laboratory's reference values. Thirty percent of the latencies in the CSE patient group and 26% in the matched control group were classified as abnormal. At group level, the decreased P300 amplitudes in CSE patients may reflect solvent-related pathophysiology. However, the P300 measured with the classical oddball paradigm does not seem to be sensitive at individual level or useful in clinical practice.

Facilitation of the spinal H-reflex by auditory stimulation in dyslexic adults.

Dyslexic subjects show a variety of mild sensory and motor deficits that have been assumed to reflect dysfunction of the large-diameter 'magnocells' in different parts of the brain. Hearing as a warning sense relies on rapidly-conducting fibers, and on the basis of the magnocellular deficit theory, we wondered whether auditory alerting would be weakened in dyslexic adults. We quantified the strength of sound-induced spinal facilitation in seven dyslexic and eight normal-reading adults by measuring the amplitudes of H-reflex, a monosynaptic spinal reflex, after loud binaural sounds. The audiospinal facilitation was of similar strength in dyslexic and control adults, indicating normal auditory alerting via cerebrospinal pathways. The slightly prolonged facilitation in dyslexics agrees with the dyslexics' general sluggishness of sensorimotor processing.

Shoulder pain and an isolated teres minor nerve lesion.

The finding of isolated teres minor denervation during examination of the shoulders using MRI occurs in 3% to 5.5% of examinations. We describe eight patients with shoulder pain, in whom electromyography revealed an isolated lesion in the motor branch of the axillary nerve to the teres minor muscle. This nerve lesion is clinically impossible to diagnose, the lack of a clear diagnosis often resulting in inappropriate treatment and therefore potentially prolonged disability. Hence, when encountering shoulder problems, neurophysiologists should examine the teres minor muscle as a matter of routine. In the MRI and ultrasound examinations of patients with shoulder problems, therefore, not only routine tendon and joint structure but also muscles should be evaluated.

Sensorimotor cortex localization: comparison of magnetoencephalography, functional MR imaging, and intraoperative cortical mapping.

PURPOSE: To prospectively evaluate magnetoencephalography (MEG) and functional magnetic resonance (MR) imaging, as compared with intraoperative cortical mapping, for identification of the central sulcus. MATERIALS AND METHODS: Fifteen patients (six men, nine women; age range, 25-58 years) with a lesion near the primary sensorimotor cortex (13 gliomas, one cavernous hemangioma, and one meningioma) were examined after institutional review board approval and written informed consent from each patient were obtained. At MEG, evoked magnetic fields to median nerve stimulation were recorded; at functional MR imaging, hemodynamic responses to self-paced palmar flexion of the wrist were imaged. General linear model analysis with contextual clustering (P < .01) was used to analyze functional MR imaging data, and dipole modeling was used to analyze MEG data. MEG and functional MR localizations were compared with intraoperative cortical mappings. The distance from the area of functional MR imaging activation to the tumor margin was compared between the patients with discordant and those with concordant intraoperative mapping findings by using unpaired t testing. RESULTS: MEG depicted the central sulcus correctly in all 15 patients, as verified at intraoperative mapping. The functional MR imaging localization results agreed with the intraoperative mappings in 11 patients. In all four patients with a false localization, the primary activation was in the postcentral sulcus region, but it did not differ significantly from the primary activation in the patients with correct localization with respect to proximity to the tumor (P = .38). Furthermore, at functional MR imaging, multiple nonprimary areas were activated, with considerable interindividual variation. CONCLUSION: Although both MEG and functional MR imaging can provide useful information for neurosurgical planning, in the present study, MEG proved to be superior for locating the central sulcus. Activation of multiple nonprimary cerebral areas may confound the interpretation of functional MR imaging results.

Somatosensory and brainstem auditory evoked potentials in cardiac arrest patients treated with hypothermia.

OBJECTIVE: To evaluate the prognostic value of short-latency median nerve somatosensory evoked potentials and brainstem auditory evoked potentials in outcome prediction for comatose cardiac arrest patients treated with hypothermia. DESIGN: Prospective, randomized, controlled trial of mild hypothermia after out-of-hospital cardiac arrest; a substudy of the European Hypothermia After Cardiac Arrest study. SETTING: Intensive care unit of a tertiary referral hospital (Helsinki University Central Hospital). PATIENTS: Sixty consecutive patients (aged 18-75 yrs) resuscitated from out-of-hospital ventricular fibrillation and comatose at 24 hrs after cardiac arrest; all patients were randomly assigned either to therapeutic hypothermia of 33 degrees C or normothermia. INTERVENTIONS: All patients received standard intensive care for at least 2 days. Patients randomized to hypothermia were cooled with an external cooling device for 24 hrs and then allowed to rewarm slowly for 12 hrs. In the normothermia group, the core temperature was kept below 38 degrees C with antipyretics and by physical means. The clinical outcome was assessed 6 months after cardiac arrest. MEASUREMENTS AND MAIN RESULTS: Somatosensory evoked potentials and brainstem auditory evoked potentials were recorded 24-28 hrs after cardiac arrest. All wave latencies were significantly prolonged in the hypothermia group. Bilaterally absent N20 waves predicted permanent coma with a specificity of 100% in both treatment groups. Brainstem auditory evoked potential recordings did not correlate with the outcome in either treatment group. CONCLUSIONS: The prognostic ability of median nerve short-latency somatosensory evoked potentials does not seem to be affected by therapeutic hypothermia. Brainstem auditory evoked potentials had no additional value in outcome prediction.