Decerebrate rigidity in acute head injury

A comprehensive study of the motor patterns, usually grouped under the heading "decerebrate rigidity," was carried out in a series of 800 patients with severe head injuries. The incidence of these manifestations was 39.6%, and when they were present chances of survival were reduced from 79.4% to 28.1%. Clinical and electromyographic investigations revealed heterogeneous and unstable motor manifestations that did not fit into the classical groups of experimental models of decerebrate rigidity. Combinations of extensor and flexor attitudes and/or responses were frequently found in same patient, but could be separated into homogeneous groups. Each recognized postural pattern had its own distinct neurological signs and prognosis. Age did not significantly affect the outcome, however, intracranial exapnding lesions (73.5%), impairment of the brain-stem oculomotor system (49.8%), and deep coma (88.9%) all contributed to an unfavorable course. Surgical treatment was effective when performed for intracranial hematomas and in patients with incomplete extensor rigidity. Good recovery was achieved in 16% of decerebrate patients, while 12.1% survived in prolonged coma or with severe disabilities. All clinical and neuropathological data suggest that extensor motor abnormalities in the acute phase of cerebral traumatic disease do not always conclusively indicate structural brain-stem damage. A critical analysis of so-called "decerebrate rigidity" (rejecting in some instances its Sherringtonian implications) may allow for a more accurate clinical assessment of the severity of head injury.

Toxic polyneuropathies in Italy due to leather cement poisoning in shoe industries. A light- and electron-microscopic study

The peripheral nerve biopsy specimens of 4 cases of toxic polyneruopathies induced by exposure to leather cement in shoe industries were studied. Analysis of the cements used in the manufacturing process proved them to contain n-hexane as a volatile substance. Light- and electron-microscopic examination of nerve biopsies showed segmental swelling of axons due to the accumulation of packed filaments and thinning of the overlying myelin sheath. Neither active nerve fibre degeneration nor regeneration were frequently seen. It has been suggested that features of so-called giant axonal neuropathy are the most common pattern of peripheral nerve degeneration in chronic n-hexane intoxication.

Opsoclonus and palatal myoclonus during prolonged post-traumatic coma. A clinico-pathologic study

A case of opsoclonus and palatal myoclonus following blunt head injury is described. The syndrome appeared 1 month after the injury and lasted unchanged until death. Postmortem examination showed the presence of widespread lesions of the brain stem affecting the dentato-rubro-olivary system. The main clinical features of the syndrome and their anatomical correlates are discussed.

[Alzheimer's disease. Histopathological and ultrastructural study of 6 cases (author's transl)]

Histologically Alzheimer's disease is chiefly characterized by senile plaques and neurofibrillary degenerations. Electron microscopy has clarified the basic morphological changes and has shed some light on the pathogenesis of the lesions. The senile plaque includes three components: neurites in various stages of degeneration, amyloid, and glial cells or processes. Degeneration of neurites is considered to represent the major change since it occurs before amyloid deposition, therefore playing a primary role in the development of the plaque: therefore the senile or neuritic plaque is the result of a neuronal disease, even though there is no evidence of perikarion injury. Neurofibrillary tangles are due to the accumulation in the neuronal cytoplasm of large clusters of abnormal neurotubules about 200 A diameter with periodic narrowings every 800 A (Twisted tubules). The nature and significance of the pathological material observed within the neurons are discussed.

Status spongiosus of rat central nervous system induced by actinomycin D

The effect on central myelin of Actinomycin D, an RNA--and, secondarily, a protein-synthesis inhibitor, has been studied by light and electron microscopy. The intracranial injection of this drug produced an extensive status spongiosus of the white matter in the cerebrum, cerebellum, brain stem and optic nerve within 48 h. The status spongiosus was due to vacuole formation within the myelin sheath and to enlargement of the extracellular space. Three types of vacuoles were observed: (a) the most common varieties formed between the inner tongue and the remainder of the myelin sheath; (b) a second variety formed by enlargement of the periaxonal space with separation of the axon from its myelin sheath, and (c) a less common type of vacuolization was due to splitting of the myelin lamellae at the interperiod line to form large intramyelinic vacuoles. Myelinic vacuoles were preceded by nuclear and cytoplasmic changes in oligodendrocytes, which included nucleolar segregation, disaggregation, and diminution in number of ribosomes. These changes were similar to those previously reported in a variety of cells exposed to Actinomycin D. It is suggested that myelin vacuoles result secondarily from the Actinomycin D inhibitory effect on oligodendroglial RNA--and protein-synthesis, rather than from a direct effect of this drug on the myelin sheath.

Sudanophilic leucodystrophy: report of a case with tigroid demyelination of the centrum ovale

A 17-year-old girl with negative familial and personal history developed a progressive neurologic disorder characterized by cortical amaurosis, metal deterioration and spastic tetraparesis. Death occurred one year after the onset of symptoms. Histopathologic examination of the C.N.S. showed the presence of extensive, discontinuous demyelination of the white matter of the centrum ovale, with preservation of perivascular myelin islets, associated with massive fat degradation, loss of axons and severe astroglial proliferation. This case belongs to the group of sudanophilic leucodystrophies, being an atypical case, a transition between pure sudanophilic leucodystrophy and the group of Pelizaeus-Merzbacher's disease.

Striato-nigral degeneration. Report of a case with an unusually short course and multiple system degenerations

A 50-year-old white woman with an 8-month history of Parkinson's syndrome which did not respond to levodopa therapy was found on pathological examination to have the topographical lesions of striato-nigral degeneration. In addition to those characteristic lesions, an associated degeneration of the optic pathways, from the level of the optic nerve to the geniculo-collicular fibers, of the corticospinal tract and of the olivo-dentate axis, were found. While offering further evidence for the concept of "multiple system degeneration", no pathogenetic relationship either to previous cases of striato-nigral degeneration or to other multiple system degenerations is implied.

Nuroaxonal degeneration induced by sodium diethyldithiocarbamate in cultures of central nervous tissue

Well myelinated cultures of newborn mouse cerebellum, exposed to varying concentrations of sodium diethyldithiocarbamate (DDC), a heavy metal chelating agent, were examined by light and electron microscopy. DDC treatment of cultures for 24-48 hours produced swellings of axons and presynaptic endings, the morphological features characteristic of dystrophic axons. The axonal swellings contained an increased amount of endoplasmic reticulum, mitochondria and dense bodies. A continued exposure to DDC induced an extensive degeneration of axons and ensheathing myelin. Glial cells, on the other hand, were structurally intact even after a long-term exposure to DDC. It is suggested that DDC produces in myelinated CNS cultures an initial enlargement of axons and presynaptic endings and then continues to induce Wallerian degeneration in axons.

[Infantile neuro-axonal dystrophy: anatomo clinical study of one case (author's transl)]

A case of Seitelberger's infantile neuroaxonal dystrophy (a rare familial neurologic disease of childhood) is described. The clinical picture is characterized by a progressive deterioration of psychomotor functions leading to flaccid paraplegia with hypotonia of axial muscles, complete involution of language, and total loss of communication with the external world; death due to recurrent unassociated disease occurred at the age of 4 years. Histology showed numerous axonal spheroids mainly in the gray matter of the C.N.S. and plurisystemic degenerations of the motor and sensory systems, of the cerebellum, of the basal ganglia, and of specific sensory system such as the optic and (reported here for the first time) of the olfactory and acoustic systems. In particular, the main histopathological findings included: 1) a characteristic distribution of axonal swellings prevailing in the posterior horn of the spinal cord and in the dorsolateral portions of the medulla oblongata, mainly at the level of the sensory nuclei; 2) demyelinization of the pyramidal tracts and of the ascendings pathways of the sensory system with fibrillar gliosis and myelin breakdown products in some areas (internal capsule, pes pedunculi, VPL thalamic nuclei); 3) severe cerebellar atrophy with almost complete loss of granule and Purkinje cells and marked fibrillary gliosis; 4) presence of enormous amount of sudanophilic lipids in the striatum and pallidum; 5) optic, acoustic and olfactory system degeneration with demyelinization and gliosis at all levels examined and, in particular, sudanophilic lipid deposition in the optic radiations, trigone, and olfactory striae. The discussion emphasized the dying-back type of evolution of the degenerative process insofar as a) the spheroids represent a peculiar alteration of presynaptic endings (as demonstrated by electron microscopy) prevailing at the first sensory neuron, and b) in all systems involved, the degeneration is most marked at distal levels. The striato-pallidal lipophanerosis suggests that the sudanophilic lipids are, here as in other systems, parenchymal degeneration products. On the other hand, there are still many unresolved problems in this rare and complex disease, such as a) the predilection of the lesions for the sensory systems which in our case involved all three special senses; b) the extreme cerebellar atrophy; and c) the etiopathogenetic substrate of the process. All biochemical and histochemical studies have not yielded any results up to the present.

[Progressive myoclonic epilepsy: anatomo - clinical study of a sporadic case with a marked cerebellar symptomatology (author's transl)]

A case of progressive myoclonic epilepsy (P.M.E.) is described. The clinical picture consisted of epileptic seizures, myoclonus and slight mental deterioration associated with a severe progressive cerebellar syndrome. The disease had a course of almost 20 years. Histological studies of the C.N.S. showed severe loss of Purkinje cells, sligth regressive changes in both dentate and olivary nuclei, nerve cells atrophy of anterior horn motoneurons, degeneration of Goll's and Burdach's spino-olivary and anterior spino-cerebellar tracts. Features of cellular lipidosis and/or neuronal amiloid inclusions were not seen. The case was therefore classified in the group of degenerative P.M.E. Its peculiar pathologic aspects consisted of slight but diffuse brain stem regressive changes associated with systemic degeneration involving the spino-cerebellar pathways. The clinical features of our patient emphasize the problem of differential diagnosis between. P.M.E. and D.C.M. thought of by French authors to be an autonomous entity both clinically )severe cerebellar syndrome, intentional myoclonus, absence or late appearance of epilepsy, slight or absent mental deterioration) and anatomically (primary atrophy of the dentate system). However there are many cases, similar to the one reported, which have a clinical course suggesting a diagnosis of D.C.M., but which differ neuropathologically from Hunt's syndrome because of the absence of primary atrophy of the dentate system. These borderline cases give supporting evidence to the concept of continuity between classical P.M.E. and D.C.M., as well as to the authors' opinion that 1unt's syndrome must be classified as a varient of degenerative P.M.E.