"Grumose degeneration" of the dentate nucleus. A light and electron microscopic study in progressive supranuclear palsy and dentatorubropallidoluysial atrophy

Acute benzyl alcohol intoxication: An autopsy case report

INTRODUCTION

The main mechanism of death and the pathological appearance of cases of benzyl alcohol intoxication has not been fully investigated. Autopsy reports of cases of benzyl alcohol intoxication have not been published.

CASE PRESENTATION

A 24-year-old man was found in the state of cardiopulmonary arrest at a construction site. He had been performing paint stripping. He was immediately transferred to the hospital, but he did not recover. An autopsy showed focal coloring of the skin without any major caustic injury. A histopathological investigation showed vacuolar degeneration in the epidermis and dermo-epidermal junction, and severe erosion of the tracheal and bronchial mucosa. No pathological changes in the kidney were evident. A neuropathological investigation showed central chromatolysis of neuronal cells in pontine nuclei and grumose degeneration in the cerebellar dentate nucleus. The blood content of benzyl alcohol was 780.0 μg/mL.

LESSONS

Present case suggest that multiple pathways of exposure may be associated with more rapid progression in acute benzyl alcohol intoxication, and that early and/or severe involvement of the central nervous system rather than renal dysfunction may be associated with an early death.

Pathological Appearance of a Case of Preclinical Multiple System Atrophy: A Comparison With Advanced Cases

We aimed to investigate the frequency of multiple system atrophy (MSA) in a large number of forensic autopsies and characterize the pathological appearance of preclinical MSA. We investigated a series of 1930 brains from forensic autopsies. In addition to performing immunohistochemistry for phosphorylated α-synuclein, the levels of 3 autonomic nervous system markers (catecholaminergic, serotonergic, and cholinergic) were used to assess the peripheral nerve (heart and superior cervical ganglion) and medulla oblongata. The results were compared to those of healthy control and Parkinson disease (PD) cases. Four cases (0.21%) were identified as having MSA. Cases 1-3 were symptomatic, and Case 4 was incipient; that is, although no neuronal loss was evident, the cerebellar dentate nucleus exhibited marked grumose degeneration. Immunohistochemistry revealed a marked reduction in autonomic nervous system marker levels expressed in the medulla; this reduction was more prominent in the 3 symptomatic MSA cases than in the PD case. The opposite occurred for the peripheral nerve. Case 4 exhibited mild cholinergic nerve reduction. Two cases showed possible significant pathological changes in the heart. Grumose degeneration, few oligodendroglial cytoplasmic inclusions without neuronal loss, and less reduction of autonomic nervous tissue were more prominent in the preclinical case than in symptomatic cases.

Pallidal degenerations and related disorders: an update

Neurodegenerative disorders involving preferentially the globus pallidus, its efferet and afferent circuits and/or related neuronal systems are rare. They include a variety of both familial and sporadic progressive movement disorders, clinically manifesting as choreoathetosis, dystonia, Parkinsonism, akinesia or myoclonus, often associated with seizures, mental impairment and motor or cerebellar symptoms. Based on the involved neuronal systems, this heterogenous group has been classified into several subgroups: "pure" pallidal atrophy (PPA) and extended forms, pallidonigral and pallidonigrospinal degeneration (PND, PNSD), pallidopyramidal syndrome (PPS), a highly debatable group, pallidopontonigral (PPND), nigrostriatal-pallidal-pyramidal degeneration (NSPPD) (Kufor-Rakeb syndrome /KRS), pallidoluysian degeneration (PLD), pallidoluysionigral degeneration (PLND), pallidoluysiodentate atrophy (PLDA), the more frequent dentatorubral-pallidoluysian atrophy (DRPLA), and other hereditary multisystem disorders affecting these systems, e.g., neuroferritinopathy (NF). Some of these syndromes are sporadic, others show autosomal recessive or dominant heredity, and for some specific gene mutations have been detected, e.g., ATP13A2/PARK9 (KRS), FTL1 or ATP13A2 (neuroferritinopathy), CAG triple expansions in gene ATN1 (DRPLA) or pA152T variant in MAPT gene (PNLD). One of the latter, and both PPND and DRPLA are particular subcortical 4-R tauopathies, related to progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and frontotemporal lobe degeneration-17 (FTLD-17), while others show additional 3-R and 4-R tauopathies or TDP-43 pathologies. The differential diagnosis includes a large variety of neurodegenerations ranging from Huntington and Joseph-Machado disease, tauopathies (PSP), torsion dystonia, multiple system atrophy, neurodegeneration with brain iron accumulation (NBIA), and other extrapyramidal disorders. Neuroimaging data and biological markers have been published for only few syndromes. In the presence of positive family histories, an early genetic counseling may be effective. The etiology of most phenotypes is unknown, and only for some pathogenic mechanisms, like polyglutamine-induced oxidative stress and autophagy in DRPLA, mitochondrial dysfunction induced by oxidative stress in KRS or ferrostasis/toxicity and protein aggregation in NF, have been discussed. Currently no disease-modifying therapy is available, and symptomatic treatment of hypo-, hyperkinetic, spastic or other symptoms may be helpful.

Making the diagnosis of frontotemporal lobar degeneration

CONTEXT

Autopsy evaluation of the brain of a patient with frontotemporal dementia (FTD) can be daunting to the general pathologist. At some point in their training, most pathologists learn about Pick disease, and can recognize Pick bodies, the morphologic hallmark of Pick disease. Pick disease is a type of frontotemporal lobar degeneration (FTLD), the general category of pathologic process underlying most cases of FTD. The 2 major categories of pathologic FTLD are tauopathies (FTLD-tau) and ubiquitinopathies (FTLD-U). Pick disease is one of the FTLD-tau subtypes and is termed FTLD-tau (PiD).

OBJECTIVE

To "demystify" FTLDs, and to demonstrate that subtypes of FTLD-tau and FTLD-U can be easily determined by following a logical, stepwise, histochemical, and immunohistochemical investigation of the FTD autopsy brain.

DATA SOURCES

Previously published peer-reviewed articles.

CONCLUSIONS

The hope is that this article will be a useful reference for the general pathologist faced with performing a brain autopsy on a decedent with frontotemporal dementia.

Enlargements of somatosensory-evoked potentials in progressive supranuclear palsy

OBJECTIVE

To evaluate the usefulness of the somatosensory-evoked potential (SEP) in differentiating progressive supranuclear palsy (PSP) from other movement disorders.

MATERIALS AND METHODS

The median nerve SEPs were studied in patients with PSP, Parkinson's disease and essential tremor, and in healthy controls.

RESULTS

The amplitudes of the median nerve SEPs were enlarged only in patients with PSP. In four of the 10 patients with PSP, giant SEPs were elicited either unilaterally or bilaterally.

CONCLUSIONS

The enlargement of the SEP in PSP may be useful for early differentiation of PSP, and this enlargement suggest a disease-specific dysfunction in the sensory processing mechanism of PSP which distinguishes it from other movement disorders.

An autopsy case of ornithine transcarbamylase deficiency

We present an autopsy case of ornithine transcarbamylase (OTC) deficiency with grumose degeneration in the dentate nucleus of the cerebellum. The patient had intractable neonatal convulsions and hyperammonemia from the 3rd day after birth. Diagnosis of OTC deficiency was made based on null activity of the enzyme and four-base deletions in exon 9 of the OTC gene. Death was due to sepsis as well as disseminated intravascular coagulation at 1 year and 2 months of age. Neuropathology showed multiple cystic changes and ulegyria in the bilateral frontal and parietal lobes. Multiple cysts were associated with the region, which was infiltrated with macrophages surrounded by astroglia showing palisading pattern. Ferrugination was marked in the thalamus and severe neuronal loss with astrogliotic change in the CA1-2 area of the hippocampus. Grumose degeneration was noted in the dentate nucleus of the cerebellum. This is the first report of grumose degeneration in OTC deficiency.

Hypertrophy of the inferior olivary nucleus in patients with progressive supranuclear palsy

Hypertrophic changes in the inferior olivary nuclei have been occasionally described in patients with progressive supranuclear palsy (PSP). To elucidate the incidence of olivary hypertrophy, we investigated morphologically the olives and their associated pathways in 20 autopsied cases: 11 cases of PSP, 3 cases of Machado-Joseph disease and 6 cases of dentatorubropallidoluysian atrophy (DRPLA) as control diseases that usually exhibited lesions of the cerebellofugal pathway. Olivary hypertrophy was observed in 5 of 11 PSP cases, but not in the other diseases, except for 1 case of DRPLA with an old infarct in the dentate nucleus. In the olivopetal pathway, grumose degeneration of the dentate nucleus and mild neuronal loss in the red nucleus were observed in all patients with PSP and in the control subjects. Atrophy and fibrillary gliosis of the tegmentum of the pons, including that of the bilateral central tegmental tracts, were observed in all patients with PSP, more severe in the cases with hypertrophic neurons in the olives. We speculate that a lesion that involves the central tegmental tracts may play a major role in inducing hypertrophy of the olives in patients with PSP.

Neuropathologic differentiation of progressive supranuclear palsy and corticobasal degeneration

Progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) are usually sporadic multi-system degenerations associated with filamentous tau inclusions in neurons and glia. As such they can be considered sporadic tauopathies in contrast to familial tauopathies linked to mutations in the tau gene. Mutations have not been found in the tau gene in either PSP or CBD. The clinical syndromes and neuroimaging of typical cases of PSP and CBD are distinct; however, atypical cases are described that have overlapping clinical and pathologic features. Both PSP and CBD have similar biochemical alterations in the tau protein, with the abnormal tau protein containing predominantly four-repeat tau. While there is overlap in the pathology in PSP and CBD, there are sufficient differences to continue the present day trend to consider these separate disorders. Several important pathologic features differentiate PSP from CBD. Ballooned neurons are frequent and nearly a sine qua non for CBD, but they are found in PSP at a frequency similar to that of other neurodegenerative diseases, such as Alzheimer's disease. Astrocytic lesions are different, with tufted astrocytes found in motor cortex and striatum in PSP and astrocytic plaques in focal atrophic cortices in CBD. The most characteristic neuronal tau pathology in CBD is wispy, fine filamentous inclusions within neuronal cell bodies, while affected neurons in PSP have compact, dense filamentous aggregates characteristic of globose neurofibrillary tangles. Thread-like processes in gray and white matter are much more numerous and widespread in CBD than in PSP. The brunt of the pathology in CBD is in the cerebrum, while the basal ganglia, diencephalon and brainstem are the targets of PSP. Further clinicopathologic studies will refine our understanding of these disorders and open the possibility that common etiologic factors may be identified for these unusual sporadic tauopathies.

Cerebellar dentate nucleus in Alzheimer's disease with myoclonus

Although myoclonus commonly occurs in a later stage of Alzheimer's disease (AD), the pathological basis of this symptom is still unclear. In order to elucidate the neuropathological substrate of myoclonus in AD, we quantitatively assessed neuronal density and volume, with a discrimination between small and large neurons, at the rostral and caudal parts in the cerebellar dentate nucleus of 8 AD patients with myoclonus, 10 AD patients without myoclonus and 9 controls, using stereological probes. The neuronal numerical density of the large neurons at the rostral part and of total counts (rostral and caudal parts) in the myoclonic AD group were significantly greater than in the nonmyoclonic AD group. There were no significant differences in the density of small neurons between the two AD groups. The ratio of small neurons to large neurons (S/L ratio) of total counts was significantly lower in AD with myoclonus than in AD without myoclonus. The mean neuronal volume of the large neurons at the rostral part was significantly greater in myoclonic AD than in nonmyoclonic AD. Conversely, the volume of the small neurons at the rostral part was significantly lower in myoclonic AD than in nonmyoclonic AD. This study, for the first time, shows an increase in mean volume of large neurons and a decrease in mean volume of small neurons as well as a change in the S/L ratio in the dentate nucleus in AD with myoclonus. An imbalance in the S/L ratio as well as morphological changes of these neurons in the dentate nucleus may contribute to the pathological substrate of myoclonus in AD.

The neuropathology of progressive supranuclear palsy

The macroscopical, histological, ultrastructural and immunocytochemical features of progressive supranuclear palsy (PSP) are reviewed. Recent investigations have revealed important differences in the distribution, ultrastructure and immunocytochemical profile of neurofibrillary tangles in PSP and in Alzheimer's disease. Cortical involvement, as demonstrated by the presence of tangles and neuropil threads has extended the neuropathological spectrum of PSP. Quantitative assessments of neuronal populations show neuronal loss, not only in various nuclei of the brainstem, diencephalon and cerebellum, but also in other areas, including the nucleus basalis of Meynert, substantia nigra and neostriatum. A new classification, based on neuropathological criteria, is suggested in order to take into consideration the phenotypic heterogeneity of PSP. This new classification distinguishes three types: typical, atypical and combined cases. Typical (Type 1) cases conform to the original definition of PSP. Type 2, atypical cases are variants of the histological changes characteristic of PSP: either the severity or the distribution of abnormalities, or both of these deviate from the typical pattern. Cases with combined pathology belong to type 3 group: in these the typical pathology of PSP is accompanied by lesions characteristic of another neurodegenerative or vascular disease.

Immunohistological study of grumose degeneration of the dentate nucleus in progressive supranuclear palsy

The grumose degeneration observed in the dentate nuclei of 7 cases of progressive supranuclear palsy (PSP) was studied with a panel of antibodies which included 2 neurofilaments, Tau and ubiquitin. Dentate nucleus neurons were negative with all antibodies except ubiquitin which showed a slightly positive homogeneous pattern of staining. The amorphous material surrounding swollen or normal neurons was strongly positive for neurofilament and subunits and numerous torpedoes were observed in the granular layer of the cerebellar cortex. Our results confirm that grumose degeneration consists in degeneration of terminal axons of Purkinje cells in the dentate nucleus. The positivity of dentate nucleus neurons for ubiquitin may support the concept of synaptic dysfunction between Purkinje cells and dentate nucleus neurons.

"Grumose degeneration" of Trétiakoff

We reviewed Trétiakoff's "grumose degeneration (GD)" which described pathologic cellular change in the substantia nigra (SN). This term has been occasionally used up to the mid-1960s by Greenfield et al.; it has rarely been used after the 1970s. This study emphasises the following: (1) after the 1970s, GD has sometimes been signalled in the SN under various names, such as "spheroid with foamy appearance", "granular spheroid", "saccular structure", or "foamy spheroid body"; (2) the ultrastructure of GD is unknown, being entirely different from that of typical axonal swellings (so-called "spheroids"); (3) more attention should be paid to GD in the SN because its nature has remained unclarified since the original description; and (4) "GD" in the cerebellar dentate nucleus is essentially different from Trétiakoff's GD.