Stimulus complexity enhances auditory discrimination in patients with extremely severe brain injuries

There is controversy as to what extent the processing of spectrally rich sounds in the human auditory cortex is related to the processing of singular frequencies. An informative index of the function of the auditory cortex, particularly important in neurological patients, is the mismatch negativity (MMN), a component of auditory event-related potentials. In the present study the MMN was recorded in 79 patients with extremely severe diffuse brain injuries, most of them in persistent vegetative state or minimal consciousness state. Both sinusoidal ('pure') and complex musical tones were used. Different statistical approaches converged in that musical tones elicited an MMN significantly more frequently, and of a larger amplitude, than simple sine tones. This implies that using simple stimuli in clinical populations may lead to a severe underestimation of the functional state of a patient's auditory system. The findings are also in line with behavioral and physiological data indicating independent processing of complex sounds in the auditory cortex.

[Early rehabilitation in Baden-Wurttemberg--a study of all Baden-Wurrtemberg early rehabilitation centers]

Over a period of 12 months, all persons among the 10.4 million inhabitants of the state of Baden-Württemberg were included in the study who had suffered severe brain damage and were treated in special early rehab units, comprising 147 beds for adults and 43 for children. With 830 patients admitted, the incidence of severe brain damage was 7.98/100.000 in adults and 1.11/100.000 in children. 50 to 70 year old patients were over-represented, those older than 70 years were underrepresented due to geriatric rehab facilities for the latter. Male patients dominated, while female were somewhat younger. 54% of the patients were admitted from the hospital which had performed primary care, with an average stay of 67 days. Average early rehab duration was 53 days (arithmetic average; median 40 days, some patients required up to one year). 32.8% of the patients had suffered traumatic brain damage (ICD 851, 852, 854) and 40.9% non-traumatic brain affection (ICD 430, 431, 433-438, 310, 348), including 12.2% CVA (ICD 433-438), 8.5% subarachnoid and 12.3% intracerebral hemorrhage. Severity as indexed by the early rehab Barthel index improved from an initial average of -119 to -34 at discharge. 80% of the patients showed an overall improvement (71% of them by up to 200 points and 46% by up to 100 points).

Brain potentials in human patients with extremely severe diffuse brain damage

To test higher cortical functions of neurological patients, oddball tasks are often used in which a frequent and a rare stimulus are randomly presented and a P3 brain wave is recorded to the rare stimulus. We examined 33 patients with extremely severe brain injury. Three oddball conditions were used: with two sine tones (ST), with two complex tones (CT) and with vowels 'o' and 'i'. Across all patients, CT elicited P3 more often than ST, and the occurrence of the P3 after vowels was intermediate. However, among patients who showed a distinct P3 wave, its amplitude in the subgroup with traumatic brain injury was larger to vowels than to CT. In patients with non-traumatic etiology, CT and vowels elicited a P3 of a nearly equal amplitude. Stimuli of sufficient complexity should be used when the P3 technique is applied for assessment of cortical functions in severely impaired patients.

[Subarachnoid hemorrhage caused by spinal arteriovenous angioma. Diagnostic difficulties and therapeutic possibilities]

In a young patient with spinal angioma, the diagnosis was not established until the fourth episode of bleeding. Exemplified by this case, the clinical symptomatology of spinal subarachnoid hemorrhage is described, and the diagnostic and therapeutic procedures are reviewed. In patients with SAH it is necessary to look for spinal symptoms, especially if cerebral angiography proves negative. In diagnosing a spinal SAH priority should be given to myelography and/or MRT, followed by spinal angiography.

Macro-aneurysm in the basal ganglia region

A 59-year-old female patient suddenly developed vomiting and gait disturbances followed by decreasing consciousness. CT scans revealed a hemorrhage within the left basal ganglia region with rupture into the ventricles and consecutive hydrocephalus. On angiography an aneurysm in the region of the caput nuclei caudati was shown to be the source of the bleeding. On repeat-angiography 4 months later the aneurysm was no longer visualized, probably due to thrombosis. This is an extraordinary case of a basal ganglia aneurysm comparable with the aneurysms of Willis' circle, but located in a region where generally microaneurysms--mostly combined with hypertension or moyamoya disease--can be found.

Acrocallosal syndrome: association with cystic malformation of the brain and neurodevelopmental aspects

The acrocallosal syndrome (ACS) is a rare malformation syndrome characterized by a distinct pattern of craniofacial, brain and limb anomalies. It was first described by Schinzel in 1979 and followed by 25 other cases reported in the literature. Neurodevelopmental aspects include hypotonia of prenatal onset, seizures and moderate to severe mental retardation. The condition is probably of autosomal recessive inheritance but is closely resembles the Greig cephalopolysyndactyly syndrome (GCPS), an autosomal dominantly inherited disorder mapped to the short arm of chromosome seven. We reviewed the literature for aspects of associated cystic malformations in addition to agenesis of the corpus callosum and report on another patient with ACS. Prognosis is dependent on the degree of hypotonia and early onset of epilepsy rather than the degree of craniofacial and limb malformations.

Mutism after cerebellar medulloblastoma surgery

The case of a 9-year-old boy is presented, who developed transient mutism after removal of a medulloblastoma in the region of the cerebellar vermis. The mutism disappeared within 6 months. Neither reduction of consciousness nor disturbances of caudal cranial nerves or phonation ever appeared. The case is discussed with regard to its phenomenology, pathogenesis, and etiology, corresponding case reports are also taken into consideration.

Acute bleeding into a filum terminale ependymoma

We present a case of a 63-year-old male patient who was admitted to our hospital due to an acute compression syndrome of the cauda equina. He had complained about a sciatica for at least one year. CT-diagnosis appeared to be negative, whereas a lumbar myelogram revealed a complete block at L2/3. Emergency surgery was performed, and an ependymoma of the filum terminale was removed into which it had bled massively. The case is compared to the literature findings. These relate ependymomas in the described region with acute onset more often to symptoms caused by subarachnoid bleeding. Mechanical and/or histopathological factors are discussed as the cause of acute bleeding. Spinal ependymomas represent a rare event compared to other neurosurgical diseases. Even more seldom are tumors of this kind causing an acute cauda equina compression syndrome.

Immunological diagnosis in viral infections of the central nervous system: course of antibody titres against homo- and heterologous viruses

In clinical cases suspected for viral encephalitis or meningoencephalitis, the estimation of virus-specific antibodies especially in liquor requires high sensitivity as well as specificity. With enzyme immunoassays the sensitivity in detecting antibodies has increased compared to e.g., complement fixation tests. This report concerns the determination of virus-specific antibodies with a commercial enzyme-linked immunosorbent assay (ELISA) in paired liquor/serum samples of four patients with encephalitis or meningoencephalitis. Up to six virus-specific antibodies of the IgG and IgM classes have been determined [herpes simplex virus (HSV), varicella-zoster virus (VZV), cytomegalovirus, mumps virus, measles virus, and rubella virus]. Additionally, serum samples from several patients suffering, or recovered from, diseases caused by HSV and VZV without CNS involvement have been included as controls. The results showed that besides the virus-specific antibody development (IgG and IgM) against the leading virus, i.e., principally concerned in the disease manifestation assumed to be primarily causing the disease, virus-specific antibodies of the IgG and IgM class against a heterologous virus (e.g., VZV) could also be measured with substantial titers. "Cross-reacting" antibodies to both HSV and VZV with the ELISA only appeared and were present in cases where the infection mainly affected the CNS: no such immunological "cross-reactivity" was observed in serum of individuals in "clinically silent" stages of both HSV and VZV infections. The same situation with no measurable "cross-reacting" antibodies was found in cases of acute HSV or VZV diseases where the CNS was not involved. These findings have been discussed with respect to the findings of common antigens, especially between HSV and VZV, and with respect to an unspecific stimulation of immunocompetent cells.