Protective effects of glutathione on cisplatin neurotoxicity in rats

PURPOSE

Different attempts have been made to minimize the neurotoxicity of cisplatin (DDP) and the use of "neuroprotective" drugs seems to be a promising strategy. In rats we compared the effects on the dorsal root ganglia neurons and peripheral nerves of the administration of DDP alone or in combination with glutathione (GSH), a putative "neuroprotective" drug.

METHODS AND MATERIALS

Twenty-four Wistar rats were treated with DDP alone (2 mg/kg/week) or with the same dose of DDP plus GSH (300 mg/week) for nine cycles and they were compared to 12 untreated age-matched rats. All the animals underwent either neurophysiological examination of the tail nerve or pathologic examination of the dorsal root ganglia. Analytical determination of the platinum concentration in dorsal root ganglia was also performed.

RESULTS

Morphologic and morphometric evaluations demonstrated a reduced incidence of pathologic changes in DDP plus GSH-treated rats with respect to DDP-treated ones. In agreement with the morphological findings, the platinum concentration in the dorsal root ganglia was lower and sensory nerve conduction velocity in the tail nerve less markedly decreased in the animals treated with DDP plus GSH with respect to those treated with DDP alone.

CONCLUSION

We conclude that the administration of GSH is effective in reducing the neurotoxic effects of DDP, thus supporting the preliminary results obtained in clinical trials in humans.

Long-term peripheral neurotoxicity of cisplatin in patients with successfully treated epithelial ovarian cancer

We evaluated clinically and neurophysiologically the immediate and long-term involvement of the peripheral nervous system in 22 selected patients with epithelial ovarian cancer successfully treated with DDP alone or in combination with non-neurotoxic drugs. While the motor nerves were unaffected, generally the involvement of sensory nerves was more severe at the examination performed several months after DDP discontinuation than at the evaluation performed after the "induction phase". We conclude that up to now the importance of long-term DDP-induced peripheral nerve damage has probably been underestimated. DDP-induced long-term damage is at least as severe as the immediate toxicity and, moreover, it is likely that complete recovery can occur, if ever, only years after DDP discontinuation.

Off-treatment course of cisplatin-induced dorsal root ganglia neuronopathy in rats

As yet little is known about the off-treatment course of cisplatin (CDDP) neurotoxicity. In this study we evaluated in the rat how the pathological changes in dorsal root ganglia (DRG) neurons and the electrophysiological alterations in peripheral nerves induced by chronic CDDP administration evolved after drug withdrawal. Twelve female Wistar rats were treated with CDDP and 3 of them were sacrificed 1, 5, 10 and 20 weeks after treatment. The results of the experiment indicated that: 1) the damage induced by sub-lethal doses of CDDP in the DRG neurons is reversible, 2) the first structures to be damaged are the DRG neurons (mostly their nucleoli) and 3) both damage and recovery in the follow-up period involve first the DRG neurons and subsequently the peripheral nerves.

Homozygous hypertrophic hereditary motor and sensory neuropathies

We compared 25 autosomal dominant hereditary motor and sensory neuropathy (HMSN) type I patients with 7 subjects affected by hypertrophic HMSN with non-dominant inheritance. All the autosomal dominant HMSN I cases carried the chromosome 17p11.2 duplication, providing evidence that it is widely represented in HMSN I families. The second group included: two siblings born to unrelated, unaffected parents and suffering from hypertrophic HMSN of strikingly different severity; two sisters with HMSN I phenotype, born to first-cousin unaffected parents; two brothers with HMSN III phenotype born to unrelated parents both showing HMSN II phenotype; a child with classic HMSN III phenotype, born to unrelated, unaffected parents. The 17p11.2 duplication was not found in any of the patients of the second series or in their parents. Our data provide further evidence that: HMSN III is heterogeneous and encompasses the homozygous expressions of different neuropathic genes; it is advisable to separate autosomal recessive hypertrophic HMSN from dominant HMSN Ia, because they appear to be due to different DNA mutations.

Antiepileptic drugs and peripheral nerve function: a multicenter screening investigation of 141 patients with chronic treatment. Collaborative Group for the Study of Epilepsy

One hundred forty-one adult patients treated for no less than 6 months with standard daily doses of the commonest antiepileptic drugs (AEDs) were recruited in five Italian centers and submitted to intensive clinical and electrophysiologic investigation to assess the effects of AEDs on peripheral nerves. Eighty percent of the patients were receiving monotherapy. Carbamazepine (CBZ) was the most common AED (51 cases), followed by phenytoin (PHT) (46), phenobarbital (PB) (42), and valproate (VPA) (25). Fifty-three percent of the patients had one or more symptoms of polyneuropathy (paresthesias being the most common complaint). The neurologic examination was abnormal in 32%. Electrophysiologic findings in two or more separate nerves were abnormal in 77 patients (54.6%); of these, 27 (19.1%) had abnormal neurologic findings and 21 (14.9%) also had symptoms of polyneuropathy. Sensory functions were most frequently impaired. Sural nerve biopsy was performed in 4 patients receiving monotherapy with CBZ, PHT, PB, and VPA. Except in patients receiving VPA (in whom no morphologic abnormalities were detected), mild predominantly axonal damage with secondary myelin changes was noted. A correlation was noted between polyneuropathy, age of the patient and, to a lesser extent, receipt of two or more AEDs.

Long-lasting neuropsychological changes after a single high altitude climb

Acute neuropsychological changes due to high altitude climbing without supplementary oxygen are well known. However, many climbers report vague symptoms of brain dysfunction after return to sea level suggesting that long-lasting neuropsychological impairment may ensue even after a single ascent. In this study we evaluated a series of neuropsychological functions in a group of 11 climbers who ascended over 5000 m. Besides memory, also reaction time and concentration were less efficient when the climbers were evaluated 75 days after their return to sea level, confirming that even a single high altitude climb may be harmful for central nervous system functions.

Evaluation by somatosensory evoked potentials of the neurotoxicity of cisplatin alone or in combination with glutathione

The use of high doses of cisplatin (DDP) in the treatment of different solid tumors is often prevented by the onset of a disabling sensory neuropathy. In an attempt to minimize DDP-induced neurotoxicity different schedules of DDP administration have been tested. Moreover, during the past few years some putative neuroprotective drugs have been reported as reducing DDP neurotoxicity. In this prospective, randomized study we evaluated in a series of 33 patients affected by relapsing ovarian cancer the effect on the sensory pathway of a non-conventional schedule of DDP administration as monochemiotherapy or in combination with one of the neuroprotective drugs (i.e. glutathione). The results of the neurophysiologic examinations performed before and immediately after chemotherapy suggest that these schedules besides being safe and effective in the treatment of the ovarian cancer, have an extremely low peripheral neurotoxicity.

Morphometric study of the sensory neuron and peripheral nerve changes induced by chronic cisplatin (DDP) administration in rats

We performed a morphological, morphometric and toxicological study on the spinal ganglia and peripheral nerves of the rat after chronic administration of cisplatin (cis-dichlorodiammineplatinum II; DDP) with two different schedules. Severe damage of the spinal ganglia neurons was demonstrated with predominant involvement of the nucleus and nucleolus associated with a decrease in the cell size. Morphological and morphometric changes also occurred in the sciatic and peroneal nerves with the features of axonopathy. All these changes were more marked in the group of rats which underwent the most intense DDP treatment and the tissue platinum concentrations were also higher in this group. This experimental model is the first available for chronic DDP administration in which concomitant spinal ganglia and peripheral nerve damage has been confirmed pathologically. Our study supports the hypothesis that DDP-induced peripheral nerve fiber degeneration may result from nuclear and nucleolar changes in the sensory ganglion cell perikaryon.

Sural nerve bioptic findings in essential cryoglobulinemic patients with and without peripheral neuropathy

Peripheral neuropathy often occurs in cryoglobulinemia but the pathogenesis of the peripheral nerve involvement is not completely understood, so that the relation between the reported endoneural changes and neuropathy is not clear. In this study we compared the sural nerve biopsies of 6 cryoglobulinemic patients with or without signs of peripheral neuropathy and all affected by the essential mixed type II form (ECII) and, moreover, of 8 age-matched controls. We found that in all the patients with neuropathy, axonopathy occurred and it was invariably associated with endoneural vessel damage. Moreover, the fiber losses were patchily distributed within the nerve fascicles. On the contrary both nerve fibers and vessels were normal in the patients without clinical and neurophysiological evidence of neuropathy and in controls. Our results support the hypothesis that the endoneural damage observed during ECII is not simply coincidental, but is relevant in the pathogenesis of cryoglobulinemic neuropathy. They also favor the assumption that ischemic damage of the nerve fibers occurs during ECII.

Cisplatin-induced peripheral neurotoxicity is dependent on total-dose intensity and single-dose intensity

The authors prospectively evaluated the effects of three different schedules of cisplatin (DDP) administration in 60 patients with advanced epithelial ovarian cancer. The individual total dose of DDP was 450 mg/m2 in all three groups, and the anti-cancer response at the end of treatment was similar for the different regimens. The clinical and neurophysiologic results confirmed that axonal sensory neuropathy occurred after the standard administration of DDP (75 mg/m2 in 3-week cycles) and probably not only the peripheral, but also the central sensory pathway, was involved. Although the total dose of the drug was identical, the two less conventional schedules were less neurotoxic. These results suggest that not only the total-dose intensity, but also the single-dose intensity are relevant in the onset of DDP-induced sensory neuropathy; therefore, the use of less neurotoxic schedules may prevent or reduce sensory nerve damage.

The incidence and course of paraneoplastic neuropathy in women with epithelial ovarian cancer

Sensorimotor polyneuropathy is the most common of the paraneoplastic syndromes involving the nervous system. Its incidence is high (more than 50%) in the patients undergoing neurophysiological investigation, and it is considered to be more frequent in subjects with lung and breast cancers. In this study we evaluated a series of 58 women with epithelial ovarian cancer at FIGO stages I and III. The aim of the study was to assess the incidence and characteristics of peripheral nerve involvement during the course of the disease both clinically and neurophysiologically. Our results suggest that in women with epithelial ovarian cancer (1) the incidence of subclinical polyneuropathy is high; (2) sensory involvement is predominant in stage I, but motor involvement is frequent in stage III; and (3) the incidence of peripheral nerve involvement increases with progression of the cancer.

Infantile hereditary neuropathy with hypomyelination: report of two siblings with different expressivity

We report the cases of two siblings both affected by inherited sensory-motor neuropathy of a demyelinative nature but with markedly different severity and pathological findings. The clinical, neurophysiological and morphological features in these two cases were consistent with the diagnosis of Hereditary Motor Sensory Neuropathy type 3 (HMSN 3), according to the classification of Dyck, with different expressivity. These results raise the still unsettled question of the phenotypic variants in inherited neuropathies. In fact the most severely affected of our cases had clinical and neurophysiological findings identical to those reported in cases of Congenital Hypomyelination Neuropathy (CHN), but the morphological picture in the sural nerve was inconsistent with this diagnosis. The criteria for the diagnosis and the reported cases of CHN have been reviewed.

A clinico-pathological and follow up study of 10 cases of essential type II cryoglobulinaemic neuropathy

Ten patients with essential cryoglobulinaemia type II were examined for peripheral nerve damage. In six cases distal symmetrical nerve involvement was present, while in three other cases abnormalities restricted to single nerves were found. Electrophysiological and morphological data were consistent with axonal damage, the larger myelinated fibres being most affected. Although active signs of vasculitis and immunoperoxidase staining for immunoglobulins were not present, endoneurial vessels were widely damaged, with abnormally thick endothelial cells and redundant basal membranes. These findings, together with a patchy distribution of myelinated fibre loss, suggest ischaemia as a cause of peripheral neuropathy during essential cryoglobulinaemia type II. A follow up examination, performed one year after haematologial remission, revealed that no further peripheral nerve damage had occurred.

Persistent memory impairment after high altitude climbing

High altitude climbing without supplementary oxygen is a common sporting practice and athletes have been extensively evaluated with respect to possible brain functional impairment during its performance. Little is known on the contrary about long-term effects of hypoxia on the central nervous system. We evaluated, at sea level, a group of 10 high-altitude climbers with a battery of neuropsychological tests before and 75 days after the ascent. Our results suggest the occurrence of an impairment of memory performance after return to sea-level at least in some subjects, while speech and certain practical abilities were unchanged.

MRI evaluation of a case of herpes zoster ophthalmicus with delayed contralateral hemiplegia

We report the case of a patient affected by contralateral hemiplegia during herpes zoster ophthalmicus (HZO) evaluated both with serial CT scans and with MRI. We suggest that MRI examination of patients affected by HZO could be useful for the detection of early signs of cerebral arterial damage which are not yet clinically and radiologically apparent.

Adrenoleukodystrophy. Report of a case with extremely slow progression of symptoms

Adrenoleukodystrophy (ALD) is a sex-linked disorder characterized by very long chain fatty acid accumulation in different tissues, but mainly in the adrenal cortex, gonads and nervous system. The typical symptoms are hypoadrenalism, hypogonadism and central and peripheral nervous system impairment due to demyelination. On neurological grounds visual and hearing loss associated with quadriparesis are the most common symptoms, onset in childhood and a rapidly progressive course leading to a vegetative state and death. We report the case of a 31-year-old man affected by ALD, whose neurological symptoms started at the age of 12 and showed a markedly slow progression during the following years.

Hemorrhagic infarction: risk factors, clinical and tomographic features, and outcome. A case-control study

A radiological diagnosis of hemorrhagic infarction (HI) was made in 41 of 2726 cases with cerebrovascular lesions (1.9%). The clinical records of the cases and those of 82 age- and gender-matched subjects with ischemic infarction were examined, and notes of the principal risk factors of cerebrovascular disorders, the clinico-radiologic features and the outcome of the disease were taken for comparison. Cardiac sources of emboli (atrial fibrillation, native or prosthetic valve disorders, recent myocardial infarction) were present in 44% of cases and in 24% of controls. Diabetes mellitus was recorded in 31% and 18% respectively. Thirteen percent of cases and 35% of controls gave a history of transient ischemic attacks. Stupor or coma during the acute phase and a more severe course were more common among cases. In general, HIs were significantly larger than ischemic infarcts, with mass-effect, although the size of the lesion did not seem to be related to the presence of cardiogenic embolism.

Intracerebral hemorrhage following intravenous administration of epinephrine

We report a case of intracerebral hemorrhage (ICH) in a young man following intravenous self-administration of epinephrine. Arteriography evidenced normal intracranial vessels, and namely excluded the presence of vascular malformations which could have been implicated in the pathogenesis of ICH. We believe that the main pathogenetic agent in this case was the sudden rise in arterial blood pressure. This report aims at underlying the severe implications of non-medical use of sympathomimetic drugs.

Histological features of nerve fibers and endoneural vessels in a case of Wegener's granulomatosis

A sural nerve biopsy obtained from a patient with Wegener's granulomatosis and overt clinical signs of polyneuropathy showed degenerative changes of both myelinated and unmyelinated fibers. The pathological aspects were those of an axonopathy. Endoneural vessels were also involved, showing changes either in the endothelial cells, which were thickened and enriched with organelles, or in the basal membrane, which was reduplicated and thicker than in the controls. There were no cellular infiltrates nor was there clear evidence of fibrosis in the vascular wall. We suggest that peripheral neuropathy in Wegener's granulomatosis could be secondary to endoneural vessel changes on the basis of a possible immune complex action.

Endoneural vessel involvement in hypothyroidism

Light-microscope findings and pathological ultrastructural changes in sural nerve biopsies from two patients affected by hypothyroidism, one with overt signs of peripheral neuropathy, the other asymptomatic, were studied. In both patients the endoneural vessels showed clear pathological changes similar to those of other metabolic neuropathies, but more marked in the symptomatic patient. It is proposed that the changes observed in the nerve fibers in hypothyroid neuropathy are secondary to changes in the endothelial cells and in the vessel wall.