Methanol poisoning: acute MR and CT findings in nine patients

Secondary parkinsonism associated with focal brain lesions

Focal imaging abnormalities in patients with parkinsonism suggest secondary etiology and require a distinctive clinical approach to diagnosis and treatment. We review different entities presenting as secondary parkinsonism associated with structural brain lesions, with emphasis on the clinical course and neuroimaging findings. Secondary parkinsonism may be due to vascular causes, hydrocephalus, space-occupying lesions, metabolic causes (including acquired hepatocerebral degeneration, diabetic uremic encephalopathy, basal ganglia calcifications, osmotic demyelination syndrome), hypoxic-ischaemic brain injury, intoxications (including methanol, carbon monoxide, cyanide, carbon disulfide, manganese poisoning and illicit drugs), infections and immune causes. The onset can vary from acute to chronic. Both uni-and bilateral presentations are possible. Rigidity, bradykinesia and gait abnormalities are more common than rest tremor. Coexisting other movement disorders and additional associated neurological signs may point to the underlying diagnosis. Neuroimaging studies are an essential part in the diagnostic work-up of secondary parkinsonism and may point directly to the underlying etiology. We focus primarily on magnetic resonance imaging to illustrate how structural imaging combined with neurological assessment can lead to diagnosis. It is crucial that typical imaging abnormalities are recognized within the relevant clinical context. Many forms of secondary parkinsonism are reversible with elimination of the specific cause, while some may benefit from symptomatic treatment. This heterogeneous group of acquired disorders has also helped shape our knowledge of Parkinson's disease and basal ganglia pathophysiology, while more recent findings in the field garner support for the network perspective on brain function and neurological disorders.

Beyond the Shadows: Unravelling the Menace of Methanol-Induced Posterior Reversible Encephalopathy Syndrome

Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiological illness characterized by neurological symptoms and reversible changes in neuroimaging. We discuss the case of a 45-year-old patient with an alcohol use disorder who presented with an altered mental state in the emergency room. Home-made alcohol, known to contain significant quantities of methanol, was recently consumed in excess by the said patient. The diagnosis of PRES was supported by magnetic resonance imaging (MRI), which showed bilateral hyperintense regions in the temporo-occipital lobes and diffuse cerebral edema. The development of PRES and chronic alcoholism, as well as binge drinking and possible endothelial dysfunction, are all highlighted in this case study. For individuals with PRES, early identification and adequate care are essential for reducing complications and improving outcomes.

Awareness raising and dealing with methanol poisoning based on effective strategies

Intoxication with methanol most commonly occurs as a consequence of ingesting, inhaling, or coming into contact with formulations that include methanol as a base. Clinical manifestations of methanol poisoning include suppression of the central nervous system, gastrointestinal symptoms, and decompensated metabolic acidosis, which is associated with impaired vision and either early or late blindness within 0.5-4 h after ingestion. After ingestion, methanol concentrations in the blood that are greater than 50 mg/dl should raise some concern. Ingested methanol is typically digested by alcohol dehydrogenase (ADH), and it is subsequently redistributed to the body's water to attain a volume distribution that is about equivalent to 0.77 L/kg. Moreover, it is removed from the body as its natural, unchanged parent molecules. Due to the fact that methanol poisoning is relatively uncommon but frequently involves a large number of victims at the same time, this type of incident occupies a special position in the field of clinical toxicology. The beginning of the COVID-19 pandemic has resulted in an increase in erroneous assumptions regarding the preventative capability of methanol in comparison to viral infection. More than 1000 Iranians fell ill, and more than 300 of them passed away in March of this year after they consumed methanol in the expectation that it would protect them from a new coronavirus. The Atlanta epidemic, which involved 323 individuals and resulted in the deaths of 41, is one example of mass poisoning. Another example is the Kristiansand outbreak, which involved 70 people and resulted in the deaths of three. In 2003, the AAPCC received reports of more than one thousand pediatric exposures. Since methanol poisoning is associated with high mortality rates, it is vital that the condition be addressed seriously and managed as quickly as feasible. The objective of this review was to raise awareness about the mechanism and metabolism of methanol toxicity, the introduction of therapeutic interventions such as gastrointestinal decontamination and methanol metabolism inhibition, the correction of metabolic disturbances, and the establishment of novel diagnostic/screening nanoparticle-based strategies for methanol poisoning such as the discovery of ADH inhibitors as well as the detection of the adulteration of alcoholic drinks by nanoparticles in order to prevent methanol poisoning. In conclusion, increasing warnings and knowledge about clinical manifestations, medical interventions, and novel strategies for methanol poisoning probably results in a decrease in the death load.

Bilateral basal ganglia hemorrhage: a systematic review of etiologies, management strategies, and clinical outcomes

Bilateral basal ganglia hemorrhages (BBGHs) represent rare accidents, with no clear standard of care currently defined. We reviewed the literature on BBGHs and analyzed the available conservative and surgical strategies. PubMed, Scopus, Web of Science, and Cochrane were searched following the PRISMA guidelines to include studies reporting patients with BBGHs. Clinical characteristics, management, and outcomes were analyzed. We included 64 studies comprising 75 patients, 25 (33%) traumatic and 50 (67%) non-traumatic. Traumatic cases affected younger patients (mean age 35 vs. 46 years, p=0.014) and males (84% vs. 71%, p=0.27) and were characterized by higher proportion of normal blood pressures at admission (66% vs. 13%, p=0.0016) compared to non-traumatic cases. Most patients were comatose at admission (56%), with a mean Glasgow Coma Scale (GCS) score of 7 and a higher proportion of comatose patients in the traumatic than in the non-traumatic group (64% vs. 52%, p=0.28). Among the traumatic group, motor vehicle accidents and falls accounted for 79% of cases. In the non-traumatic group, hemorrhage was most associated with hypertensive or ischemic (54%) and chemical (28%) etiologies. Management was predominantly conservative (83%). Outcomes were poor in 56% of patients with mean follow-up of 8 months. Good recovery was significantly higher in the traumatic than in the non-traumatic group (48% vs. 17%, p=0.019). BBGHs are rare occurrences with dismal prognoses. Standard management follows that of current intracerebral hemorrhage guidelines with supportive care and early blood pressure management. Minimally invasive surgery is promising, though substantial evidence is required to outweigh the potentially increased risks of bilateral hematoma evacuation.

Outbreak of methanol-induced optic neuropathy in early COVID-19 era; effectiveness of erythropoietin and methylprednisolone therapy

BACKGROUND

Methanol is a highly toxic, non-potable alcohol. Outbreaks of methanol toxicity occur due to its fraudulent addition to alcoholic beverages as a cheaper substitute for ethanol. Recently, alongside the coronavirus disease 2019 (COVID-19) pandemic, rumors circulated on social media that consuming alcohol can prevent or cure the virus, leading to a COVID-19 and methanol-induced optic neuropathy (MON) syndemic.

AIM

To investigate the impact of erythropoietin (EPO) on the outcomes of patients diagnosed with MON.

METHODS

In this prospective study, 105 patients presenting with acute bilateral visual loss secondary to methanol intoxication were enrolled from March to May 2020 at Farabi Eye Hospital. A comprehensive ocular examination was conducted for all participants. Recombinant human EPO and methylprednisolone were administered intravenously to all patients for three consecutive days.

RESULTS

The mean age of the participants was 39.9 years (± 12.6). Ninety-four patients were male and eleven were female. The mean pre-treatment best corrected visual acuity (BCVA) improved from 2.0 ± 0.86 to 1.39 ± 0.69 logarithm of the minimum angle of resolution post-treatment (P < 0.001), with significant improvement observed in all age categories and genders (P < 0.001). Visual acuity improvement was also significant regardless of whether the patient presented before or after 72 h (P < 0.001), and the post-treatment BCVA remained significant at all monthly follow-up visits (P < 0.001).

CONCLUSION

EPO and methylprednisolone therapy have been shown to be effective in improving visual outcomes in patients with MON when administrated within the first month of exposure. Public awareness efforts are necessary to prevent further outbreaks of methanol toxicity in the current COVID-19 era.

Methanol poisoning outbreak in Saudi Arabia: a case series

Background

Outbreaks of methanol poisoning have been described in the medical literature in different regions around the world. Even though in Saudi Arabia a few outbreaks of methanol poisoning have occurred, they remain undocumented. Herein, we describe several cases of methanol poisoning in Saudi Arabia with the goal of increasing awareness about the dangers of methanol poisoning among healthcare staff.

Case presentation

Nine middle-aged Saudi patients (five men aged 24, 26, 27, 36, and 49 years and four females aged 19, 20, 24, and 25 years) were admitted to our emergency department after alcohol consumption. All patients presented with severe metabolic acidosis and some visual impairment. Treatment was initiated based on the clinical suspicion of methanol intoxication because of laboratory test limitations and time constraints. Patients showed improvement and favorable hospital outcomes after aggressive empirical treatment.

Conclusions

Many social and cultural factors influence the lack of reporting of methanol poisoning cases in Saudi Arabia. We believe it is important to document these outbreaks to increase the knowledge among healthcare providers and promote public health awareness. A high index of suspicion and the development of local public health networks to monitor, survey, follow-up, and facilitate data exchange can help healthcare providers recognize and aggressively treat affected individuals. Early empiric and aggressive management can greatly decrease morbidity and mortality despite challenges and limited resources.

Late hemorrhagic transformation of brain lesions in case with methanol intoxication

Methanol intoxication can be occurred as accidental or suicidal ingestion or intentional ingestion through abuse. Formic acid is the primary toxic metabolite which causes high anion gap metabolic acidosis and end-organ damage in the human body. Here we presented a 46-year-old man who loss of consciousness on the 23rd day of hospitalization and his cranial computed tomography revealed bilateral subcortical hemorrhages. This case indicates us an example of late appearance of hemorrhagic transformation in methanol intoxication.

Alcohol consumption epidemic and its complications during the COVID-19 pandemic in Khuzestan Province, Iran; 2020

Background: After unprecedented demand for ethanol in the pandemic, profiteers used methanol for making illegal alcoholic drink. Methods: This cross-sectional descriptive-analytical study investigated the effects of methanol poisoning on 400 patients who referred to hospitals affiliated with Ahvaz Jundishapur University of Medical Sciences from March 20 to September 20, 2020. Results: Ninety-eight-point five percent of patients had consumed alcohol for social reasons and only 0.3% had used it as a measure to avoid COVID-19. Eighty-seven percent of the patients used homemade alcohol bought from peddlers. The most common clinical symptom was gastrointestinal disorders (64.8%) and the most common complications were vision problems (12.3%). Ten-point-six percent (42 patients) of the patients died. The most important factors affecting mortality risk were dyspnea, neuropathic problems, abnormal radiological findings, dialysis, abnormal blood pressure, vision problems and dizziness. Conclusions: Informing the public about the risks of using homemade alcoholic beverages is essential if the associated disability and mortality has to be avoided.

Methanol poisoning during COVID-19 pandemic; A systematic scoping review

Objective

In this systematic scoping review, it was aimed to assess the epidemiology of methanol poisoning, clinical findings and patients' management, causes, and recommendations regarding prevention or reduction of methanol poisoning during COVID-19 pandemic.

Methods

Three Electronic databases [Medline (accessed from PubMed), Scopus, and Science Direct] were searched systematically from December 01, 2019 to September 10, 2020, using MESH terms and the related keywords in English language. Considering the titles and abstracts, unrelated studies were excluded. The full texts of the remained studies were evaluated by authors, independently. Then, the studies' findings were assessed and reported.

Results

Total of 86 articles were obtained within the first step of searching, and 64 ones remained after removing the duplications. Through the title and abstract screening, 35 were removed. Finally, after reading the full text of the remained articles, 15 ones included in data extraction. Most of the previous reported evidence (13/15) were letter to editor, commentary and short reports. None of them were interventional, and none of them followed the patients. Findings were summarized in four categories: 1) epidemiology; 2) clinical findings and patients' management; 3) causes; and 4) recommendation regarding prevention or reduction of methanol poisoning during COVID-19 pandemic.

Conclusion

The recent outbreak is the largest methanol mass poisoning outbreak throughout Iran and the world in recent decades. The causes of methanol poisoning during the COVID-19 pandemic are intertwined, and most of them are modifiable by health policy makers. Building trust, educating and warning, as well as controlling and monitoring are three main recommendation for prevention or reduction of methanol poisoning.

Comparing the Clinical Characteristics, Laboratory Findings, and Outcomes between Epidemic and Episodic Methanol Poisoning Referrals; a Cross-sectional Study

Introduction:

Due to illegal manufacturing and sales of alcoholic beverages, epidemic outbreaks of methanol poisoning may occur. The aim of this study was to determine if there were differences in the severity, course of poisoning, and outcomes between methanol-poisoned patients admitted during an outbreak versus those who were admitted following episodic exposures.

Methods:

The present retrospective study was performed in a single referral poisoning center between March 2018 and March 2019 in patients with confirmed methanol poisoning. During this time, in addition to episodic cases of methanol intoxication, there were three methanol poisoning outbreaks. Outbreaks were characterized by an unexpected increase in the number of methanol-poisoned patients in a short period of time, which impacted resources and decision-making. The two groups were compared regarding their severity of poisoning, sessions of hemodialysis, and clinical outcomes.

Results:

Outbreak cases had a higher level of methanol than episodic cases. Odds of being dialyzed more than once was 5.4 times higher in the cases presenting during an outbreak (95% CI 2.1-14.0; p=0.001). Mean hospital stay, intubation/mechanical ventilation, and death were similar between the two groups. An evaluation of the alcoholic beverage samples available in the Iranian black market during the outbreak showed a 7-percent methanol concentration with no ethanol content.

Conclusions:

Poisoning risk may be higher during methanol outbreaks due to the higher methanol concentrations, requiring more hemodialysis sessions for persistent metabolic acidosis. In addition to alcohol dehydrogenase blockade, careful risk assessment of all methanol poisonings can assist with stratifying the priority for, and duration of, hemodialysis to optimize outcomes.

Methanol poisoning as a new world challenge: A review

BACKGROUND

Methanol poisoning (MP) occurs often via ingestion, inhalation, or dermal exposure to formulations containing methanol in base. Clinical manifestations of MP include gastrointestinal symptoms, central nervous system (CNS) suppression, and decompensated metabolic acidosis occurred with blurred vision and early or late blindness.

OBJECTIVE

This study reviewed the clinical manifestations, laboratory and radiology findings, and treatment approaches in MP.

DISCUSSION

Methanol is usually rapidly absorbed after ingestion and metabolized by alcohol dehydrogenase (ADH), then distributed to the body water to reach a volume distribution approximately equal to 0.77 L/kg. It is also eliminated from the body as unchanged parent compounds. Clinical manifestations of MP alone initiate within 0.5-4 h after ingestion and include gastrointestinal symptoms and CNS suppression. After a latent period of 6-24 h, depending on the absorbed dose, decompensated metabolic acidosis occurs with blurred vision and early or late blindness. Blurred vision with normal consciousness is a strong suspicious sign of an MP. The mortality and severity of intoxication are well associated with the severity of CNS depression, hyperglycemia, and metabolic acidosis, but not with serum methanol concentration. After initial resuscitation, the most important therapeutic action for patients with known or suspected MP is correction of acidosis, inhibition of ADH, and hemodialysis.

CONCLUSION

Since MP is associated with high morbidity and mortality, it should be considered seriously and instantly managed. Delay in treatment may cause complications, permanent damage, and even death.

COVID-19 and Alcohol Poisoning: A Fatal Competition

In March 2020, concurrently with the outbreak of coronavirus disease 2019 (COVID-19) in Iran, the rate of alcohol poisoning was unexpectedly increased in the country. This study has attempted to make an overall description and analysis of this phenomenon by collecting credible data from the field, news, and reports published by the emergency centers and the Iranian Ministry of Health. The investigations showed that in May 20, 2020, more than 6150 people have been affected by methanol poisoning from whom 804 deaths have been reported. A major cause of the increased rate of alcohol poisoning in this period was actually the illusion that alcohol could eliminate the coronaviruses having entered the body. It is of utmost importance that all mass media try to dismiss the cultural, religious, and political considerations and prepare convincing programs to openly discuss the side-effects of forged alcohol consumption with the public, especially with the youth. It must be clearly specified that "consuming alcohol cannot help prevent COVID-19."

The outbreak of methanol intoxication during COVID-19 pandemic: prevalence of brain lesions and its predisposing factors

During the COVID-19 pandemic, methanol-containing beverages' consumption has risen because people mistakenly believed that alcohol might protect them against the virus. This study aimed to evaluate the prevalence and predisposing factors of brain lesions in patients with methanol toxicity and its outcome. A total of 516 patients with confirmed methanol poisoning were enrolled in this retrospective study, of which 40 patients underwent spiral brain computed tomography (CT) scan. The presence of unilateral or bilateral brain necrosis was significantly higher in the non-survival group (p = 0.001). Also, intracerebral hemorrhage (ICH) and brain edema were prevalent among patients that subsequently died (p = 0.004 and p = 0.002, respectively). Lower Glasgow Coma Scale (GCS) was related to a higher mortality rate (p = 0.001). The mortality rate in chronic alcohol consumption was lower than the patients who drank alcohol for the first time (p = 0.014). In conclusion, increasing the number of methanol poisoning and its associated mortality and morbidity should be considered a threat during the COVID-19 pandemic.

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.

The Methanol Poisoning Outbreaks in Iran 2018

AIMS

To present epidemiological data, probable causes and lessons learned from the outbreak of methanol poisoning in Iran in September 2018, and relate this to the increasing incidence of methanol poisoning worldwide over recent decades.

METHOD

Analysis of all available reliable field information, official news reports and reports from the country's forensic medicine organization and the Ministry of Health.

RESULTS

Overall, 768 people in Iran were documented as poisoned from September 7 to October 7 2018 by consuming an informal alcohol containing methanol, of whom 76 died (10.1% fatality rate); 460 subjects attended state hospitals due to acute methanol poisoning of whom 42 (9.13%) died. Those who were hospitalized comprised 177 subjects (38.4%), with 241 subjects (52.3%) seen and discharged. Males comprised 93% of the deaths. About 41% of those poisoned were aged 25-36. Outbreaks were reported in 21 provinces.

CONCLUSION

These data indicate a high fatality rate of methanol poisoning in Iran, something seen also in some other countries. Considering that such outbreaks take place more in low-income and Islamic countries due to ignorance and legal constraints, it seems necessary to seek an effective educational model for raising public awareness and a fully native and early warning system in this regard to reduce the damage and enhance readiness to deal with the health effects of such outbreaks.

Hemorrhagic infarct of basal ganglia in cardiac arrest. CT and MRI findings. 2 cases

We report the CT and MRI findings in two cases of hemorrhagic infarct of the basal ganglia (BG), following out-of-hospital cardiac arrest (CA). In case 1, Brain-CT realized at day 2 showed bilateral and almost symmetric hemorrhagic infarct of the BG and infarct of the tectum of the mesencephalon. In case 2, MRI realized at day 6 showed hemorrhagic infarct of both lenticular nuclei on T2 GE images. In both cases there was no medical history and the cardiovascular and the coagulation profile were normal. In these cases, the lesions are observed earlier than reported in a few previous radiological cases. Similar lesions have been reported in pathological studies. These lesions seem occur early after CA. Reperfusion is probably responsible for the hemorrhagic transformation. The reason why some patients present either BG or brainstem infarct or both remains unclear. Bilateral and symmetric hemorrhagic infarct of the BG, especially of the Lenticular nuclei, and infarct of the dorsal pons and mesencephalic tegmentum seem to be a characteristic feature of profound and prolonged hypotension or of CA.

Intracranial Hemorrhage in Methanol Toxicity: Challenging the Probable Heparin Effect during Hemodialysis

Brain hemorrhages are rare complications of acute methanol poisoning. There is a debate on association of brain hemorrhage in methanol toxicity and application of systemic anticoagulation during hemodialysis (HD). A 70-year-old male presented to us with severe metabolic acidosis and a methanol level of 7.6 mg/dL. Ethanol and folinic acid were administered, and HD was performed. Brain computed tomography (CT) scan which was normal on presentation showed extensive bilateral subcortical supratentorial hypodensities on the 3^rd day after commencing the treatment. However, the next CT scan performed 2 weeks later revealed expanding hemorrhagic transformation in previous hypodensities. Hemorrhagic changes could not be explained by patient's coagulation profile on the 3^rd day. Anticoagulation agents such as heparin are used routinely during a dialysis session to prevent clot formation in dialysis circuits. This case is possibly questioning the role of heparin in hemorrhagic brain lesions of methanol intoxication.

Toxic leukoencephalopathies, including drug, medication, environmental, and radiation-induced encephalopathic syndromes

Toxic leukoencephalopathies can be secondary to the exposure to a wide variety of exogenous agents, including cranial irradiation, chemotherapy, antiepileptic agents, drugs of abuse, and environmental toxins. There is no typical clinical picture, and patients can present with a wide array of signs and symptoms. Involvement of white matter is a key finding in this scenario, although in some circumstances other high metabolic areas of the central nervous system can also be affected. Magnetic resonance (MR) imaging usually discloses bilateral and symmetric white matter areas of hyperintense signal on T2-weighted and fluid-attenuated inversion recovery images, and signs of restricted diffusion are associated in the acute stage. In most cases, the changes are reversible, especially with prompt recognition of the disease and discontinuation of the noxious agent. Either the MR or clinical features may be similar to several nontoxic entities, such as demyelinating diseases, leukodystrophies, hepatic encephalopathy, vascular disease, hypoxic-ischemic states, and others. A high index of suspicion should be maintained whenever a patient presents recent onset of neurologic deficit, searching the risk of exposure to a neurotoxic agent. Getting to know the most frequent MR appearances and mechanisms of action of causative agents may help to make an early diagnosis and begin therapy, improving outcome. In this review, some of the most important causes of leukoencephalopathies are presented; as well as other 2 related conditions: strokelike migraine attacks after radiation therapy syndrome and reversible splenial lesions.

Bilateral optic neuropathy with bilateral putaminal lesions: a case report

Bilateral optic neuropathy with bilateral putaminal lesions may be caused by methanol or cyanide poisoning or mitochondrial disorders including Leber hereditary optic neuropathy and Leigh syndrome. We report the case of a 34-year-old Japanese man who developed bilateral visual loss 5 days after the development of gastrointestinal symptoms. Magnetic resonance imaging of the brain on admission revealed high-intensity signal areas in the bilateral putamina on diffusion-weighted and T2-weighted images as well as a high-intensity signal area in the left middle cerebellar peduncle that had been identified 3 years previously. We diagnosed bilateral optic neuropathy with bilateral putaminal lesions caused by preceding infection-triggered demyelination. We administered methylprednisolone, but his vision did not recover.

Successful Kidney Transplant from Methanol-Intoxicated Donors

The well-described disparity between the need for and the supply of organs suitable for transplant is growing. Because of this disparity, mortality of patients listed for transplant is increasing. Donors who die of intoxication (including victims of methanol poisoning) represent less than 1% of suitable donors and might be used to increase the supply of organs. They are often not accepted as donors by transplant specialists, because of concerns about patients' outcomes with these grafts. Three cases of fatal methanol intoxication that resulted in transplants of 6 kidneys are evaluated.

A guide to diagnosis and treatment of Leigh syndrome

Leigh syndrome is a devastating neurodegenerative disease, typically manifesting in infancy or early childhood. However, also late-onset cases have been reported. Since its first description by Denis Archibald Leigh in 1951, it has evolved from a postmortem diagnosis, strictly defined by histopathological observations, to a clinical entity with indicative laboratory and radiological findings. Hallmarks of the disease are symmetrical lesions in the basal ganglia or brain stem on MRI, and a clinical course with rapid deterioration of cognitive and motor functions. Examinations of fresh muscle tissue or cultured fibroblasts are important tools to establish a biochemical and genetic diagnosis. Numerous causative mutations in mitochondrial and nuclear genes, encoding components of the oxidative phosphorylation system have been described in the past years. Moreover, dysfunctions in pyruvate dehydrogenase complex or coenzyme Q10 metabolism may be associated with Leigh syndrome. To date, there is no cure for affected patients, and treatment options are mostly unsatisfactory. Here, we review the most important clinical aspects of Leigh syndrome, and discuss diagnostic steps as well as treatment options.

Methanol and ethylene glycol intoxication

Accidental or intentional ingestion of substances containing methanol and ethylene glycol can result in death, and some survivors are left with blindness, renal dysfunction, and chronic brain injury. However, even in large ingestions, a favorable outcome is possible if the patient arrives at the hospital early enough and the poisoning is identified and appropriately treated in a timely manner. This review covers the common circumstances of exposure, the involved toxic mechanisms, and the clinical manifestations, laboratory findings, and treatment of methanol and ethylene glycol intoxication.

Methanol poisoning: characteristic MRI findings

Acute methanol intoxication is not an unusual poisoning. It can have serious neurological sequelae. We emphasize how neuroimaging can help in distinguishing methanol poisoning from other causes of acute unconsciousness in alcoholic patients such as hypoglycemic brain damage and carbon monoxide poisoning or head injury, which are frequently observed in alcoholic patients and are also responsible for altered sensorium. The most important findings in MR brain imaging in methanol poisoning have been bilateral putaminal hemorrhagic necrosis. Other less common findings are subcortical and deep white matter lesions, cerebral and cerebellar cortical lesions, and midbrain lesions, cerebral and intraventricular hemorrhage, and even enhancement of necrotic lesions, we found almost the entire spectrum of MRI findings in this patient with methanol poisoning. Neurological sequelae can entail the course and prognosis in methanol poisoning. The patient died because of ventilator-associated pneumonia that developed in the course of prolonged hospitalization.

A case of methanol intoxication caused by methomyl pesticide ingestion

When clinicians treat patients with pesticide poisoning, they often pay attention only to the chief toxic agent and ignore the toxicity of the pesticide’s additives or solvents. Occasionally, however, a solvent (e.g. methanol) may itself be the cause of poisoning. We report a case of acute methanol intoxication that occurred after ingestion of a methomyl pesticide that contained methanol as an additive. A 49-year-old man was brought to the emergency department in an unconscious state after ingestion of 20 ml of a carbamate pesticide (chief ingredient: methomyl; active ingredient: methanol). Upon arrival, he was semicomatose and did not breathe spontaneously; however, his cholinesterase level was within normal limits and cholinergic symptoms were not observed. High anion gap metabolic acidosis was present. His blood ethanol level was 74.8 mg/dL. The urine methanol level was 55.60 mg/dL, and urine ethanol level was 22.0 mg/dL. He was treated with hemodialysis; subsequently, his metabolic acidosis resolved and he returned to normal mental status. We guessed that methanol, as the solvent of the methomyl, had produced the symptoms. When treating pesticide-poisoned patients, clinicians should identify the solvent used in the pesticide, because solvents such as methanol may exacerbate the symptoms of poisoned patients.

Hyperglycemia is a strong prognostic factor of lethality in methanol poisoning

Methanol poisoning is seen in the form of isolated episodes, or intentional ingestion and epidemics. Despite its efficient treatment, methanol poisoning has high morbidity and mortality rates. So far, several studies have been performed to identify the prognostic factors in methanol poisoning. Recently, during the treatment of patients with methanol poisoning, we observed that patients' blood glucose levels were high on presentation to the hospital, particularly in those who expired. Through a literature search, we found that no studies have been performed on blood glucose levels or hyperglycemia in methanol poisoning. Therefore, the present retrospective study was done as a preliminary investigation to understand whether there was a meaningful relationship between methanol poisoning and blood glucose level on presentation, and also if hyperglycemia could be considered as a prognostic factor for mortality. In this retrospective study, a review of the hospital charts was performed for all patients who were treated for methanol poisoning from March 2003 to March 2010 in two hospitals in Tehran, Iran. Those with definitive diagnosis of methanol poisoning, no history of diabetes mellitus, and normal or low body mass index (<25) were included. Patients' demographic information, clinical manifestations, time elapsed between ingestion and presentation, blood glucose level on presentation (before treatment), results of arterial blood gas analysis, and the clinical outcome were recorded. Statistical analysis was done using SPSS software (version 17, Chicago, Illinois, USA) and application of Mann-Whitney U test, Pearson's chi-square test, Pearson correlation coefficient (r), receiver operating characteristic (ROC) curve, and logistic regression. P values less than 0.05 were considered as the statistically significant levels. Ninety-five patients with methanol poisoning met the inclusion criteria and were included in the study. Of these, 91 (96%) were male and 4 (4%) were female. Mean age was 31.61 ± 14.3 years (range, 13 to 75). Among the 95 patients, 68 survived (72%) and 27 expired (28%). Median blood glucose level was 144 mg/dL (range, 75 to 500). There was no significant statistical correlation between blood glucose level and time of treatment, age, pCO(2), or serum bicarbonate concentration, but blood glucose level had a statistically significant correlation with pH (r = -0.242, P = 0.02) and base deficit (r = 0.230, P = 0.03). The mean blood glucose level was 140 ± 55 and 219 ± 99 mg/dL in the survivor and non-survivor patients, respectively (P < 001). Considering the cutoff level of 140 mg/dL for blood glucose and using logistic regression analysis, and adjusting according to the admission data with significant statistical difference in the two study groups, the odds ratio for hyperglycemia as a risk factor for death was 6.5 (95% confidence interval = 1.59-26.4). Our study showed that blood glucose levels were high in methanol poisoning and even higher in those who died in comparison with the survivors. Therefore, hyperglycemia might be a new prognostic factor in methanol poisoning, but further studies are needed to determine whether controlling hyperglycemia has therapeutic consequences.

Outcomes of visual disturbances after methanol poisoning

INTRODUCTION

Methanol poisoning and toxic optic neuropathy is still seen worldwide. Little attention has been paid to the persistent visual disturbances following methanol poisoning. We aimed to evaluate the outcomes of visual disturbances in methanol-poisoned patients referred to us with visual disturbances.

METHODS

This retrospective observational case series evaluated the outcomes of visual disturbances in patients with methanol poisoning hospitalized in Loghman Hakim and Hazrat Rasoul Akram hospitals between March 2003 and October 2009. Medical charts were evaluated for age, gender, time between consumption and hospital presentation, gastrointestinal symptoms, abnormal neurological findings at presentation and during hospital admission, arterial blood gas results, treatment modalities, history of chronic diseases, and status of vision at presentation and discharge from the hospital. The patients or their relatives were contacted 1 year after the admission date of the last patient and questioned about the status of the patients' vision at the time of hospital discharge, after discharge, and at the time of phone contacts.

RESULTS

A total of 50 patients with methanol poisoning and visual disturbances at presentation survived. Thirty-seven cases were followed; 16 showed visual disturbance improvement before hospital discharge, and 21 had visual disturbance after discharge. Visual disturbances were classified into two groups: severe to total blindness and blurred/snowfield vision. Patients were also grouped into one of four categories: group I: patients whose blurred or snowfield vision completely recovered within up to a maximum of 2 weeks after discharge (n=7); group II, the patients who were blind at the time of discharge (n=5) and partially recovered within a maximum of 3-4 weeks; group III, the patients who were blind at the time of discharge and gained no improvement in their vision (n=5); group IV, who were blind at the time of discharge, partially recovered within few days to approximately 1 month and experienced reduced vision and blindness after about a maximum of 9 months (n=4). Patients whose visual disturbances improved with treatment and the patients in group I were considered as transient (n=23) and groups II, III, and IV as permanent visual disturbance cases (n=14). Significant difference was not seen in age, sex, elapsed time to presentation, gastrointestinal symptoms, abnormal neurological and CT findings, and arterial blood gas results at presentation between the transient and permanent visual disturbance groups. No association existed between the visual disturbance and abnormal neurological and CT findings.

CONCLUSION

Blurred or snowfield vision in methanol poisoning resolved. However, outcomes of the blindness cannot be predicted. Insome patients, blindness improves but these patients eventually experience reduced vision afterwards.

Features of Neurotoxicity on Brain CT of Acutely Intoxicated Unconscious Patients

Diagnostic imaging is a valuable device in clinical management of poisoned patients presenting to emergency units in a comatose state. Some toxic agents have adverse effects on the central nervous system (CNS). Non-contrast computed tomography (CT) of the brain, as an available diagnostic method with a high resolution, can provide useful information about structural disturbances of unconscious patients with suspected drug or chemical intoxication. The authors would describe various presentations of toxic substances detected on the brain CT scans of ten patients with acute intoxication. While non-specific, CT findings of low-attenuation lesions in the basal ganglia, infarctions in young patients, or diffuse edema should raise suspicion for poisoning or overdose.