Thalamic dementia: an example of primary astroglial dystrophy of Seitelberger.

Pure thalamic dementia is highly uncommon and typically demonstrates widespread loss of neurons throughout the thalamus associated with reactive gliosis. This report describes an autopsy case in which there is widespread gliosis of subcortical white matter, focal hippocampal sclerosis and a unique proliferation of protoplasmic astrocytes in the thalamus, with limited bilateral focal loss of neurons. The alterations of the protoplasmic astrocytes consist of proliferation of perivascular feet surrounding blood vessels and velate sheets which surround individual neurons. It is proposed that the astrocytic alterations, or astrocytic dystrophy, constitute the primary and critical pathologic-change, sufficiently severe to produce dementia in the presence of a relatively intact neuronal population.

Pituitary adenoma: a DNA flow cytometric study of 192 clinicopathologically characterized tumors.

A clinically, immunohistochemically and ultrastructurally characterized series of 192 pituitary adenomas was analyzed for DNA content by flow cytometry. Results were assessed not only relative to tumor immunotype, size, and invasiveness, but also with frequency of recurrence. Case selection was non-random; males predominated (1.8:1) and the ratio of macro-to-microadenomas was 4.2:1. Female patients were slightly younger and, in all adenoma categories, less often had invasive tumors: PRL (15%/30%), ACTH (17%/44%), LH/FSH (8%/27%) and null cell adenomas (0%/27%). With the exception of prolactin cell adenomas, similar proportions of macroadenomas and invasive tumors in all tumor subtypes were diploid and non-diploid. Prolactin adenomas differed in that tumors of males showed a high rate of non-diploidy (65%); such tumors were predominantly macroadenomas, but only 28% were invasive. Among GH-containing tumors 78% were macroadenomas, 40% were nondiploid, and the frequency of invasive macroadenomas was higher (49%) than in PRL tumors (21%). ACTH adenomas were mainly microadenomas (81%), their rate invasion (29%) and of non-diploidy being low (14%). Among "non-functioning" (LH/FSH, null cell adenomas), LH/FSH-producing tumors were all macroadenomas, but with low rates of invasion (23%) and non-diploidy (9%). Null cell adenomas, nearly all macroadenomas, had similar low invasion rate (21%), but were more often non-diploid (39%). In all adenoma subgroups S-phase fractions were higher in non-diploid adenomas by an overall ratio of 2.1:1. Prolactin adenomas showed the highest (15.2%) and LH/FSH adenomas the lowest (5.6%) mean S-phase fraction. When compared to long-term follow-up, neither this parameter nor ploidy correlated with tumor size or invasiveness. Lastly, long-term follow-up showed ploidy to be an unreliable predictor of tumor persistence or recurrence.

Dementia: the University of Oklahoma autopsy experience.

The brain from 98 consecutive patients with the clinical diagnosis of dementia were examined at autopsy in a standardized fashion. Alzheimer's Disease was present in 79 of the cases, 76%, but represented the only diagnosis in 41%. Thus, almost 60% had another associated pathologic disorder. Cerebral amyloid angiopathy (CAA) represented the single largest subset, present in 25 cases. 40% were accompanied by either 1) small, microscopic infarcts or cortical scars, or 2) small collections of macrophages containing hemosiderin or small hemorrhages. CAA occurred with both atherosclerotic cortical infarcts and arteriolosclerotic subcortical pallor or lacunar infarcts. Alzheimer's Disease occurred with Diffuse Lewy Body (DLB) Disease in 13 cases. DLB Disease did not occur as a distinct entity, and thus may represent the second largest subset of Alzheimer's Disease. Both Alzheimer's Disease and DLB Disease accounted for dementia in Parkinson's Disease. Almost 25% of all cases had a disorder other than Alzheimer's Disease.

Pediatric eighth cranial nerve schwannoma without evidence of neurofibromatosis.

Schwannomas of the eighth cranial nerve are rare in children. We report a 4 10/12 - year-old girl with no evidence of neurofibromatosis who presented with facial droop. Radiographic studies revealed a large cerebellopontine angle tumor. At surgery, the tumor was attached to the eighth cranial nerve and histologically was a schwannoma. This is the youngest reported case of unilateral eighth cranial nerve schwannoma in a patient without the stigmata of neurofibromatosis.

Primary intracerebellar osteosarcoma arising within an epidermoid cyst.

The authors report a case of a primary extraskeletal osteosarcoma arising within an epidermoid cyst in the parenchyma of the cerebellum in a 64-year-old woman. On initial presentation, the tumor involved the midline cerebellum without attachment to the surrounding dura mater or calvarium. Complete medical and radiologic evaluation failed to reveal a primary skeletal or other extraskeletal osteosarcoma. To our knowledge, this is the first reported case of a primary extraskeletal osteosarcoma within the cerebellum. Osteosarcoma as a primary brain tumor is exceedingly rare, and only three cases (all occurring within the cerebral hemispheres) have been reported previously. The histogenesis of primary sarcomas of the brain is not evident. The associated finding of an epidermoid cyst suggests the tumor originated from a teratoma.

Alzheimer's disease as a defect of neuronal autotrophism: a hypothetical analogy with amateur radio operation.

Amyloid precursor protein appears to be a signaling protein that plays a role in neuronal autotrophism, indicating integrity of the nerve terminal and synapse. Analogous to amateur radio operation with a damaged antenna in which further attempts to improve signal propagation can result in damage to the radio equipment, abnormal signaling by the secreted amyloid precursor protein stimulates compensatory metabolic activity in the neuron that ultimately leads to paired helical filament formation (neurofibrillary tangles) and further neuronal dysfunction and death.

Agenesis of cerebellum associated with arrhinencephaly.

Complete cerebellar agenesis or aplasia is an extremely rare condition with few previously reported cases. We identified a 38-week gestation infant with microcephaly who had complete cerebellar agenesis associated with arrhinecephaly. There was complete lack of the efferent and afferent limbs of the cerebellum, including the nuclei of the basis pontis, the inferior olivary nuclei, ascending spinal and medullary afferents, deep cerebellar nuclei and their afferents, and the red nucleus. Although complete cerebellar agenesis is rare, cerebellar hypoplasia is more common and can be sporadic, asymmetric, or represent clinically, genetically, and pathologically diverse examples of primary cerebellar or vermian hypoplasia.

Rhabdomyolysis following electrical injury.

Severe electrical injury is often associated with acute rhabdomyolysis, evident from massively elevated serum creatine (CK) levels, along with presence of other muscle fiber constituents in the serum and urine, resulting specifically in hyperkalemia, hyperphosphatemia, and myoglobinuria. The acute medical care of the patient with electrical injury must include addressing supportive therapy for the rhabdomyolysis (more fully reviewed in other articles in this issue of Seminars), but understanding the underlying pathophysiology of rhabdomyolysis may allow for the future development of improved therapeutic modalities.

In situ DNA hybridization study of 'primary' cytomegalovirus (CMV) oophoritis.

We report the case of a 50 year old woman with metastatic breast carcinoma refractory to chemotherapy who died of candidal septicemia after autologous bone marrow transplantation. Although there was no apparent active cytomegalovirus (CMV) infection (negative cultures and serology for active infection), autopsy revealed histologic evidence of CMV inclusions limited to both ovaries. DNA in situ hybridization was performed on multiple organs, and additional foci of infection in one fallopian tube and the adrenal glands were detected. Previous reports of isolated CMV oophoritis may represent sampling error. An ascending route of infection is suggested. Tubo-ovarian changes due to CMV infection may occur more frequently than suspected; they are difficult to diagnose because even actively CMV infected cells may not be detected by routine histology alone, and because, after the active infection 'heals', no evidence of the virus can be found on histologic examination.

Alzheimer's disease: pathophysiology and the hope for therapy.

The approximately 4.5 million Alzheimer's disease victims in the United States represent a major public health problem resulting in annual expense topping $100 billion, with the Oklahoma share being about $500 million. This problem will be even larger as the baby boomer generation reaches the ages of maximum prevalence of Alzheimer's disease. Research has provided only meager insights into this devastating disease, but has permitted some rational hypotheses concerning potential treatment. Still, the definitive diagnosis of Alzheimer's disease requires pathologic confirmation. In interviews with families following the autopsy, it is apparent that the disease is poorly understood by both the family members and many of the health care workers with which they have dealt. Thus, this review (based upon the questions raised by families and their physicians) examines the currently understood mechanisms and pathogenesis of Alzheimer's disease, the hereditary patterns, and the hope for therapy.

Midline cerebral dysgenesis, dysfunction of the hypothalamic-pituitary axis, and fetal alcohol effects.

OBJECTIVE: Neuropathologic evaluation was performed on an infant with fetal alcohol effects. DESIGN: Coronal brain sections and representative tissue blocks stained with hematoxylin-eosin, silver stain, and immunocytochemical stains for hypothalamic and pituitary hormones were evaluated for neuropathologic abnormalities. PATIENT: A 2.5-month-old American Indian girl who had been exposed to first-trimester maternal binge alcohol abuse died after persistent problems of growth failure, sodium imbalance, aberrant temperature regulation, respiratory distress, and seizures. RESULTS: Autopsy revealed severe microcephaly, hypertelorism, midfacial hypoplasia, a high-arched palate, shortened palpebral fissures, and a small brain. The frontal lobes were fused anteriorly; olfactory bulbs and tracts were absent; and optic nerves were hypoplastic. An enlarged and bulbous hypothalamus obscured the pituitary gland. The thalamus and caudate nuclei were fused across the midline. Posteriorly, the single ventricle split to form rudimentary lateral horns. The anterior corpus callosum, septum pellucidum, fimbria, and fornices could not be identified. The anterior commissure and supraoptic nuclei were microscopically present. Many Purkinje cells were horizontally positioned, with abnormal dendritic structure. The posterior pituitary lobe was absent, and the infundibulum was flanked by a hypoplastic adenohypophysis and a large subarachnoid heterotopia. Immunocytochemical studies identified only vasopressin and neurophysin in the hypothalamus and only growth hormone and prolactin in the pituitary gland. CONCLUSION: To our knowledge, an association between fetal alcohol effects and a complex cerebral anomaly with features of incomplete holoprosencephaly and septo-optic dysplasia has not previously been reported and suggests a possible common pathogenesis needing further study.

A modified Da Fano silver stain for demonstration of neurons and dendrites in glycol methacrylate-embedded brain tissue.

Golgi impregnation techniques are commonly used for characterization of neurons and their dendritic and axonal processes. Most of the widely used techniques require processing of fresh brain tissues, which limits the amount of material available for study. Additionally, the stained blocks must be subsequently embedded in paraffin, which produces considerable cellular shrinkage and distortion artifacts. Modification by one investigator of an early silver impregnation technique, designed to demonstrate the Golgi apparatus, allowed demonstration of neurons and their dendritic processes. Our further modification of the later technique, along with embedding of the stained tissue in glycol methacrylate, permits detailed examination of neurons and their processes in formaldehyde-fixed neonatal human brains. In cerebellar sections, this modified technique impregnates nearly all Purkinje cells, elucidating the fine structural detail of the developing neuronal dendritic tree and spines.

Rhabdomyolysis in childhood. A primer on normal muscle function and selected metabolic myopathies characterized by disordered energy production.

Patients with rhabdomyolysis present an important clinical problem. In acute episodes immediate treatment may be necessary to prevent significant morbidity and mortality. Evaluation of affected patients necessitates an understanding of basic muscle pathophysiology and of the variety of disturbances that can interfere with muscle energy metabolism. The physician must then pursue a systematic stepwise evaluation (Table 6) that includes obtaining relevant history and laboratory studies, as well as arranging for appropriate provocative testing and muscle biopsy. Once the diagnosis is established, patient and family counseling is necessary, particularly in genetic disorders. Unfortunately, specific therapies have not proven entirely successful, and treatment generally has been directed at reducing the severity of rhabdomyolytic episodes.

Selective type II muscle fiber hypertrophy in severe infantile spinal muscular atrophy.

The diagnostic muscle biopsy finding in severe infantile spinal muscular atrophy (Werdnig-Hoffmann disease, SMA type 1) is considered to be large-group atrophy with isolated clusters of hypertrophic type I myofibers. We present a unique case of severe infantile spinal muscular atrophy with selective hypertrophy of type II myofibers. A male infant presented at age 2 months with breathing difficulties and by age 4 months was hypotonic and weak. Electromyography revealed denervation in all extremity muscles, and nerve conduction velocities were normal but with small compound muscle action potentials. Quadriceps muscle biopsy revealed many hypertrophied type II myofibers (myofibers with a mean least diameter of 25.4 microns). In contrast, the largest type I myofibers were 20 microns in least diameter (mean diameter, 14.9 microns), and there was a normal-size population of type II fibers (mean diameter, 15.7 microns). In addition, sheets of atrophic type I and type II fibers averaged 2.0 microns in least diameter. Sural nerve biopsy was normal. Breathing difficulties progressed, with death ensuing at age 5 1/2 months. Autopsy revealed atrophy of ventral spinal roots with normal dorsal roots. There was loss of anterior horn cells, while remnant neurons were reduced in size. No other pathologic changes were identified. This case indicates that in severe infantile spinal muscular atrophy, relative sparing of the motor units with type II myofibers may occur.

Perineurial cell ensheathement of muscle fibers: a new syndrome of fatigable muscle weakness mimicking myasthenia gravis.

Many newly discovered pathological and physiological variants of neuromuscular junction function have been identified. We report a case of a myasthenia gravis-like syndrome with onset of ptosis at age six years and eventual evaluation for peripheral weakness twenty years later. Subsequent muscle biopsy showed a previously unreported finding of perineurial cell ensheathement of the muscle fibers. We suggest that the ensheathement of the muscle cells by perineurial cells may alter the microenvironment interfering with neuromuscular transmission.