The outer neomembrane of chronic subdural hematoma.

Thomas Willis recognized the entity of the chronic subdural hematoma (CSH) more than 300 years ago. Modern observations of the ultrastructure of normal meninges and the CSH outer neomembrane, combined with techniques of radioactive red blood cell labeling and chemical analysis of CSH fluid, have provided insight into the pathophysiology of this entity. The outer membrane evolves as a reaction to cleavage of the dural border cell layer of the meninges. Interaction between the components of the outer neomembrane and CSH fluid contributes to the growth of the outer membrane and recurrent hemorrhaging.

Intradural convexity chondroma: a case report and review of diagnostic features.

Intradural convexity chondromas are slow-growing tumors of young adults and children. Their symptoms are due to their size and degree of mass effect. They are extra-axial, avascular masses without peritumoral edema. CT and magnetic resonance resonance imaging of the head and cerebral angiography are helpful in diagnosis. Treatment is surgical resection.

Fulminant CNS perivascular lymphocytic proliferation: association with sargramostim, a hematopoietic growth factor.

Sargramostim (GM-CSF) therapy was instituted in a 49-year-old woman with hepatitis C on chronic interferon alpha-2b therapy. Within two weeks, she developed progressive confusion, lethargy, and gait disturbance. At autopsy 4 months later, diffuse perivascular nonmonoclonal lymphoid infiltrates were demonstrated throughout the central nervous system (CNS). As the use of hematopoietic growth factors in clinical practice increases, potential adverse effects, such as the fulminant CNS lymphocytic proliferation in this patient, are more likely to be encountered.

Exertional myalgia syndrome associated with diminished serum ammonia elevation in ischemic exercise testing.

A 36-year-old man with chronic severe exertional myalgias had a normal serum lactate elevation and diminished serum ammonia elevation on an ischemic forearm exercise test (IFET). The IFET is commonly performed in the evaluation of patients with complaints of exertional myalgias, cramps, and rhabdomyolysis. The finding of a normal serum lactate elevation and a diminished serum ammonia elevation after ischemic exercise is usually considered indicative of myoadenylate deaminase deficiency. However, myoadenylate deaminase activity was normal in this man's muscle biopsy specimen. This case suggests that a diminished serum ammonia elevation in the IFET is not always indicative of myoadenylate deaminase deficiency, a disorder of ammonia production. A diminished serum ammonia elevation in the IFET could also reflect an impairment of net ammonia efflux from muscle into blood.

Delayed diffuse upper motor neuron syndrome after compressive thoracic myelopathy.

A 54-year-old man developed progressive spastic paraparesis beginning 2 weeks after a back injury caused by a subacute compressive thoracic myelopathy attributable to a post-traumatic arachnoid cyst. Three to 18 months after surgical decompression of the thoracic arachnoid cyst, the patient developed a diffuse predominantly upper motor neuron syndrome characterized by spastic quadriparesis, pseudobulbar paresis, and pseudobulbar affect. Retrograde corticospinal tract degeneration and upper motor neuron death after spinal cord injury is recognized. This case suggests that focal upper motor neuron injury can occasionally precipitate diffuse upper motor neuron dysfunction.

Myotonia associated with sarcoidosis: marked exacerbation with pravastatin.

A 37-year-old man with sarcoidosis developed severe electrical and clinical myotonia while taking pravastatin for hypercholesterolemia. Myotonia associated with sarcoidosis is rare. Pravastatin is associated with myotonia in animals. This case suggests that sarcoidosis and pravastatin, two entities not frequently associated with myotonia, may interact in a synergistic manner to produce severe clinical myotonia in humans.

Alexander's disease: unique presentation.

Subacute necrotizing encephalomyelopathy (Leigh syndrome) refers to a nebulous disease entity characterized by lactic acidosis, a wide variety a clinical manifestations, and a consistent conglomeration of pathologic findings. Several abnormalities in metabolism have been delineated in association with Leigh syndrome, but many cases have no identified metabolic abnormality. We report a case that clinically, metabolically, and neuroradiologically appeared to be Leigh syndrome. In addition, our patient exhibited other unusual clinical findings, including ocular motility abnormalities. Neuropathologically, however, the diagnosis of Alexander's disease was confirmed. A review of the literature failed to find other cases of Alexander's disease reported with the metabolic abnormalities and clinical manifestations with which our patient presented.

Progress in neuropathology of the neuronal ceroid lipofuscinoses.

Since the last, 6th, International Congress on Neuronal Ceroid-Lipofuscinoses, neuropathological advances in neuronal ceroid lipofuscinoses (NCL) have been made in several areas: (1) In adult NCL (ANCL) lipopigments have now been repeatedly confirmed to contain subunit c of mitochondrial ATP synthase and even sphingolipid activators (saposins). ANCL lipopigments have also been confirmed in extracerebral tissues including skin, skeletal muscle, and spleen, but not yet lymphocytes (2). Among circulating blood cells not only B cells and subclasses of T lymphocytes, i.e., CD4(+), CD8(+), and CD56 cells, but also monocytes have been found to contain NCL lipopigments, indicating that this precursor cell in the digesting macrophage system also has an impaired metabolic catabolism for lipopigments (3). Immunohistochemical studies indicate that microglial reaction in NCL brain is limited to resident microglia without contribution by circulating monocytes (4). The granular osmiophilic deposit (GROD) type of NCL has now been established not only in infantile, but also in late-infantile, juvenile, and protracted-juvenile NCL (5). A European Tissue Registry established within the framework of a European Concerted Action on Neuronal Ceroid-Lipofuscinosis may form the basis for additional collaborative studies on NCL, including both biopsy and autopsy tissues.

Focal rhabdomyolysis and brachial plexopathy: an association with heroin and chronic ethanol use.

A 22-year-old man presented with acute swelling of the left neck and associated weakness of the left arm upon awakening after having snorted heroin. He had consumed large amounts of ethanol regularly for 7 years. Serum creatine kinase was greater than 19,000 units/l. A diagnosis of focal rhabdomyolysis and left brachial plexopathy was made. Focal rhabdomyolysis with associated plexopathy is an uncommon but recognized complication of acute heroin use. Chronic ethanol use may have a "sensitizing" role in the pathogenesis of this syndrome.

Ultrastructure of the retina in adult neuronal ceroid lipofuscinosis.

A 33-year-old woman died of biopsy-proven adult neuronal ceroid lipofuscinosis (NCL) or Kufs' disease marked by fingerprint and curvilinear lipopigments in neural and nonneural cell types. She had never experienced visual impairment or shown electroretinographic abnormalities. At autopsy, her retina appeared intact without degeneration at the light-microscopic level, but nerve cells in different layers were loaded with lipopigments of the granular type. This appears to be the third ultrastructural study of the retina in a patient with adult NCL, a former one showing preservation of the retina, another retinal degeneration. Thus, only further molecular genetic data will clarify the nosology of adult NCL with and without retinal degeneration.

Ethanol level differential between postmortem blood and subdural hematoma.

Alcohol use is a major risk factor for accidental injury and death. However, when death occurs several hours after injury, ethanol in the blood may be absent or low. Ethanol in sequestered hematomas has been used to retrospectively implicate alcohol as a contributing factor at the time of injury. A 69-year-old man died from a large acute subdural hematoma. He had been seen in a hospital emergency department 8 to 12 hours before his death for treatment of two lacerations (one on the head) that occurred during a fall. Postmortem blood ethanol was 0.07%, and subdural hematoma ethanol was 0.04%. This ethanol level differential between the postmortem blood and the subdural hematoma indicates that this man had consumed alcohol after being released from the hospital.

Giant intracranial and extracranial cavernous malformation. Case report.

Massive enlargement of an extracerebral cavernous malformation and extension across tissue planes is very uncommon. The authors present the case of a 49-year-old woman with a giant cavernous malformation in the left frontotemporal area. It progressively enlarged during several decades, extended through the calvaria to the extradural space, and was surgically treated. The lesion may have originated in the soft tissue or the skull. The locations of cavernous malformations in various parts of the body are reviewed and their mechanisms of growth are discussed. Surgical excision is the treatment of choice.

Neuropathology of aging.

The brain undergoes many gross and histopathologic changes with advancing age. Some of the changes seen with aging are also found in demented individuals, especially patients with Alzheimer's disease. The extent to which Alzheimer's disease and aging are truly different processes remains to be determined. The morphologic features that seem most clearly to distinguish between aging and Alzheimer's disease are the neurofibrillary tangles and senile plaques. The distinction can be further refined by determining the immunocytochemical and ultrastructural composition of the degenerating nerve processes in the neuritic plaques.

Myoclonus epilepsy with ragged red fibers and multiple mtDNA deletions.

In a patient with clinical features of myoclonus epilepsy with ragged red fibers (MERRF), molecular genetic analysis of mitochondrial DNA did not show either of the two point mutations typically associated with MERRF but did show multiple deletions by Southern blot. This case further illustrates the heterogeneity observed with mtDNA mutations.

Entirely intracanalicular meningioma: contrast-enhanced MR findings in a rare entity.

We report an unusual case of an entirely intracanalicular meningioma in a 51-year-old woman. Contrast-enhanced MR images showed an enhancing lesion filling the lateral portion of the left internal auditory canal. Our findings suggest that meningiomas should be considered in the differential diagnosis of entirely intracanalicular masses.

Massive osteolysis of the skull and upper cervical spine. Case report and review of the literature.

Massive osteolysis is a type of idiopathic osteolysis in which there is spontaneous onset of bone resorption. Almost any bone in the body can be affected. The authors present the case of a 62-year-old man diagnosed with massive osteolysis of the occipital bone and the upper two cervical vertebrae. Despite extensive pneumocephalus, no neurological sign or spinal instability was evident. In this case 4000 cGy of radiation in 200-cGy fractions was administered to the diseased area while the patient was kept in a Miami-J collar. At the 2-year follow-up examination, arrest of the disease process and new bone formation was evident on radiographic studies.