Motor neuron disease and optic neuropathy after acute exposure to a methanol-containing solvent mixture

Efficiency of 123I-ioflupane SPECT as the marker of basal ganglia damage in acute methanol poisoning: 6-year prospective study

CONTEXT

Investigate whether ¹²³I-ioflupane SPECT (DaT SPECT) has the potential as a marker of basal ganglia damage in acute methanol poisoning.

METHODS

Prospective, single-centre, cohort study of patients with confirmed methanol poisoning was conducted. DaT SPECT was performed twice with semi-quantification using DaTQUANT^TM and MRI-based volumetry was calculated. Specific binding ratios (SBR) of striatum, caudate nucleus, and putamen were correlated with laboratory parameters of outcome, volumetric data, and retinal nerve fibres layer (RNFL) thickness measurements.

RESULTS

Forty-two patients (mean age 46.3 ± 4.2 years; 8 females), including 15 with MRI-detected putamen lesions (group I) and 27 patients with intact putamen (group II), underwent DaT SPECT. Volumetry was calculated in 35 of the patients assessed. SBR values for the left putamen correlated with putamen volume (r = 0.665; p < 0.001). Decreased bilateral SBR values were determined for the striatum and the putamen, but not for the nucleus caudate, in group I (p < 0.05). Significant correlation was observed between the SBR of the posterior putamen and arterial blood pH (r = 0.574; p < 0.001) and other toxicological parameters of severity of poisoning/outcome including serum lactate, glucose, and creatinine concentrations (p < 0.05). The SBR of the posterior putamen positively correlated with the global RNFL thickness (p < 0.05). ROC analysis demonstrated a significant discriminatory ability of SBR of the posterior putamen with AUC = 0.753 (95%CI 0.604-0.902; p = 0.007). The multivariate regression model demonstrated that arterial blood pH, age, and gender were the most significant factors associated with SBR of the posterior putamen.

CONCLUSION

DaT SPECT demonstrates significant potential for the diagnosis of methanol-induced basal ganglia damage.

Late Functional and Morphological Findings after Methylalcohol Poisoning

AIM

The aim of the study was to determine the morphological and functional findings in a patient after methanol poisoning. Examination methods: The patient (male, 38 years old) was suffered methanol poisoning in eight years ago (2012). The following tests and examinations were performed: neurological visual field XR test (Medmont M700), retinal nerve fibre layer (RNFL), ganglion cell complex (GCC) and peripapillary vessel density (all using Avanti RTvue, Optovue), pattern electroretinography (PERG) and pattern visual evoked potential (PVEP) examination according to ISCEV methodology (Roland Consult Instrument) and brain MRI examination (Philips Achieva Dstream 3 T).

RESULTS

The biggest changes were found in RNFL and VD. PERG also showed damage to retinal ganglion cell axons. In left eye we determined decrease in oscillations (in comparison with contralateral eye) at N35-P50 and P50-N95. VEPs in both eyes were significantly reduced, almost inconspicuous in the left eye. Extension of latency time of P100 was not identified. Functional MRI showed a bilateral decrease in voxel activity with a greater decrease in the left eye. There were postmalatical changes in the dorsal parts of the putamen on MRI. The width of the optic nerve and chiasm was physiological.

CONCLUSION

Asymmetric damaging of RNFL and cortical centres of the brain were determined. We registered large pathological changes in VD, which are probably responsible for the deepening of optic nerve excavation and further loss of nerve fibers of retinal ganglion cells, which have not yet been described in the literature. Following these results is possible to define direct damage of nerve structures and blood vessels by toxins of methanol metabolism in the acute stage and upcoming reparation processes in following periods.

Tongue fasciculations with denervation pattern in osmotic demyelination syndrome: a case report of diagnostic dilemma

Background

The pathogenesis of osmotic demyelination syndrome is not completely understood and usually occurs with severe and prolonged hyponatremia, particularly with rapid correction. It can occur even in normonatremic patients, especially who have risk factors like alcoholism, malnutrition and liver disease. Bilateral tongue fasciculations with denervation pattern in electromyogram is a manifestation of damage to the hypoglossal nucleus or hypoglossal nerves. Tongue fasciculations were reported rarely in some cases of osmotic demyelination syndrome, but the exact mechanism is not explained.

Case presentation

A 32-year-old Sri Lankan male, with a history of daily alcohol consumption and binge drinking, presented with progressive difficulty in walking, dysphagia, dysarthria and drooling of saliva and alteration of consciousness. On examination he was akinetic and rigid resembling Parkinsonism with a positive Babinski sign. Clinical features were diagnostic of osmotic demyelination syndrome and MRI showed abnormal signal intensity within the central pons and basal ganglia. He also had tongue fasciculations. The electromyogram showed denervation pattern in the tongue with normal findings in the limbs. Medulla and bilateral hypoglossal nerves were normal in MRI.

Conclusion

We were unable to explain the exact mechanism for the denervation of the tongue, which resulted in fasciculations in this chronic alcoholic patient who developed osmotic demyelination syndrome. The hypoglossal nuclei are located in the dorsal medulla and radiologically undetected myelinolysis of the medulla is a possibility. Hypoglossal nerve damage caused by methanol or other toxic substances that can contaminate regular ethyl alcohol is another possibility, as it is known to cause neurological and radiological features similar to osmotic demyelination syndrome with long-term exposure. So these toxic substances might play a role in chronic alcoholic patients with central pontine myelinolysis.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3287-8) contains supplementary material, which is available to authorized users.

Neuromuscular Functions on Experimental Acute Methanol Intoxication

OBJECTIVE

The incidence of accidental or suicidal ingestion of methyl alcohol is high and methyl alcohol intoxication has high mortality. Methyl alcohol intoxication causes severe neurological sequelae and appears to be a significant problem. Methyl alcohol causes acute metabolic acidosis, optic neuropathy leading to permanent blindness, respiratory failure, circulatory failure and death. It is metabolised in the liver, and its metabolite formic acid has direct toxic effects, causing oxidative stress, mitochondrial damage and increased lipid peroxidation associated with the mechanism of neurotoxicity. Methanol is known to cause acute toxicity of the central nervous system; however, the effects on peripheral neuromuscular transmission are unknown. In our study, we aimed to investigate the electrophysiological effects of experimentally induced acute methanol intoxication on neuromuscular transmission in the early period (first 24 h).

METHODS

After approval by the Animal Experiment Ethics Committee of Ege University, the study was carried out on 10 Wistar rats, each weighing about 200 g. During electrophysiological recordings and orogastric tube insertion, the rats were anaesthetised using intra-peritoneal (IP) injection of ketamine 100 mg kg(-1) and IP injection of xylazine 10 mg kg(-1). The rats were given 3 g kg(-1) methyl alcohol by the orogastric tube. Electrophysiological measurements from the gastrocnemius muscle were compared with baseline.

RESULTS

Latency measurements before and 24 h after methanol injection were 0.81±0.11 ms and 0.76±0.12 ms, respectively. CMAP amplitude measurements before and 24 h after methanol injection were 9.85±0.98 mV and 9.99±0.40 mV, respectively. CMAP duration measurements before and 24 h after methanol injection were 9.86±0.03 ms and 9.86±0.045 ms, respectively.

CONCLUSION

It was concluded that experimental methanol intoxication in the acute phase (first 24 h) did not affect neuromuscular function.

Triad of visual, auditory and corticospinal tract lesions: a new syndrome in a patient with HIV infection

OBJECTIVE

A case of a rapidly progressive degeneration of the visual, auditory and corticospinal tract in a patient with a HIV infection is presented.

METHODS AND RESULTS

The HIV-infected patient suffered from severe and rapidly progressive sensorineural hearing loss, blindness, dysarthria, dysphagia and tetraparesis. MRI showed degeneration of the visual, auditory and corticospinal tract. Diffusion tensor imaging showed reduced fractional anisotropy of the corticospinal tract. HAART and other salvage therapies did not save the patient from death 5 months after the onset of the symptoms.

CONCLUSION

The triad of auditory, visual and corticospinal lesions has been described in rare syndromes and hereditary diseases. This is the first case of this syndrome associated with a HIV infection.

Electrical injury and amyotrophic lateral sclerosis: a systematic review of the literature

Electrical injury may act as a potential precipitating or risk factor for amyotrophic lateral sclerosis (ALS). A systematic review of the literature was undertaken to assess the relationship between electrical injury and the development of ALS. Information for the review was obtained using five medical databases, and from manual searching of individual papers. Patients presenting with a neurological syndrome after electrical injury, including lightning, were included and classified into four categories: ALS; progressive upper motor neurone (UMN) syndrome; progressive lower motor neurone (LMN) syndrome; and non-progressive syndrome. Linear regression and chi2 testing were used for analysis of the data. 96 individuals, comprising 44 with ALS, 1 with a progressive UMN syndrome, 7 with a progressive LMN syndrome and 44 with a non-progressive syndrome, were identified from 31 papers with publication dates between 1906 and 2002. The median interval between electrical injury and disease onset was 2.25 years for all progressive syndromes and just over 1 week for the non-progressive syndrome. The more severe the shock (excluding lightning), the more likely individuals were to have a non-progressive motor syndrome. A non-progressive spinal cord syndrome is associated with more severe electrical injury. Overall, the evidence reviewed does not support a causal relationship between ALS and electric shock.