A syndrome of bilateral symmetrical basal ganglia lesions in diabetic dialysis patients

Uremic encephalopathy manifesting with a unique MRI finding (the lentiform fork sign) in an adult male: A case report

A novel radiologic sign in patients with renal failure and uremic encephalopathy (UE) with metabolic acidosis has recently been identified as the lentiform fork sign. On magnetic resonance imaging (MRI), the "lentiform fork sign" has been described as bilateral symmetrical hyperintensities in the basal ganglia encircled by a hyperintese rim delineating the lentiform nucleus. Changes in uremic solute retention, aberrant blood-brain barrier transport, disordered vascular reactivity, altered electrolyte and acid-base balance, and altered hormone metabolism are the most likely causes of the condition. A 56-year-old male with end-stage renal disease was brought to the emergency room for a progressive change in mental status and involuntary arm movements over the previous 5 days, which were accompanied by mild dyspnea. A brain MRI was performed, and it revealed hyperintensity on T2/FLAIR in the white matter surrounding the basal ganglia. the patient was treated with dialysis and improved greatly. Intensified hemodialysis and glycemic control are the cornerstones of treating diabetic uremic syndrome (DUS) with likely reversible clinical symptoms and remission of imaging abnormalities.

Case Report: A Case of Encephalopathy Presenting the Lentiform Fork Sign on MRI in a Diabetic Dialysis Patient

Basal ganglia lesions showing an expansile high signal intensity on T2-weighted MRI are termed the lentiform fork sign. This specific finding is mainly observed in diabetic patients with uremic encephalopathy with metabolic acidosis, although there are also reports in patients with ketoacidosis, dialysis disequilibrium syndrome, intoxication, and following drug treatment (e.g., metformin). A 57-year-old Japanese man on chronic hemodialysis for 4 years because of diabetic nephropathy was admitted to our hospital for relatively rapid-onset gait disturbance, severe dysarthria, and consciousness disturbance. Brain T2-weighted MRI showed the lentiform fork sign. Hemodialysis was performed the day before admission, and laboratory tests showed mild metabolic (lactic) acidosis, but no uremia. Surprisingly, metformin, which is contraindicated for patients with end-stage kidney disease, had been prescribed for 6 months in his medication record, and his sluggish speaking and dysarthria appeared gradually after metformin treatment was started. Thus, the encephalopathy was considered to be related to metformin treatment. He received hemodialysis treatment for 6 consecutive days, and his consciousness disturbance and dysarthria improved in 1 week. At the 8-month follow-up, the size of the hyperintensity area on MRI had decreased, while the mild gait disturbance remained. Considering the rapid onset of gait and consciousness disturbance immediately before admission, diabetic uremic syndrome may also have occurred with metformin-related encephalopathy, and resulted in the lentiform fork sign, despite the patient showing no evidence of severe uremia on laboratory data.

Treatable Hyperkinetic Movement Disorders Not to Be Missed

Hyperkinetic movement disorders are characterized by the presence of abnormal involuntary movements, comprising most notably dystonia, chorea, myoclonus, and tremor. Possible causes are numerous, including autoimmune disorders, infections of the central nervous system, metabolic disturbances, genetic diseases, drug-related causes and functional disorders, making the diagnostic process difficult for clinicians. Some diagnoses may be delayed without serious consequences, but diagnosis delays may prove detrimental in treatable disorders, ranging from functional disabilities, as in dopa-responsive dystonia, to death, as in Whipple's disease. In this review, we focus on treatable disorders that may present with prominent hyperkinetic movement disorders.

Case Report: A Case of Encephalopathy Presenting the Lentiform Fork Sign on MRI in a Diabetic Dialysis Patient

Basal ganglia lesions showing an expansile high signal intensity on T2-weighted MRI are termed the lentiform fork sign. This specific finding is mainly observed in diabetic patients with uremic encephalopathy with metabolic acidosis, although there are also reports in patients with ketoacidosis, dialysis disequilibrium syndrome, intoxication, and following drug treatment (e.g., metformin). A 57-year-old Japanese man on chronic hemodialysis for 4 years because of diabetic nephropathy was admitted to our hospital for relatively rapid-onset gait disturbance, severe dysarthria, and consciousness disturbance. Brain T2-weighted MRI showed the lentiform fork sign. Hemodialysis was performed the day before admission, and laboratory tests showed mild metabolic (lactic) acidosis, but no uremia. Surprisingly, metformin, which is contraindicated for patients with end-stage kidney disease, had been prescribed for 6 months in his medication record, and his sluggish speaking and dysarthria appeared gradually after metformin treatment was started. Thus, the encephalopathy was considered to be related to metformin treatment. He received hemodialysis treatment for 6 consecutive days, and his consciousness disturbance and dysarthria improved in 1 week. At the 8-month follow-up, the size of the hyperintensity area on MRI had decreased, while the mild gait disturbance remained. Considering the rapid onset of gait and consciousness disturbance immediately before admission, diabetic uremic syndrome may also have occurred with metformin-related encephalopathy, and resulted in the lentiform fork sign, despite the patient showing no evidence of severe uremia on laboratory data.

Age-Dependent Signal Intensity Changes in the Structurally Normal Pediatric Brain on Unenhanced T1-Weighted MR Imaging

BACKGROUND AND PURPOSE

Various pathologic and nonpathologic states result in brain parenchymal signal intensity changes on unenhanced T1-weighted MR imaging. However, the absence of quantitative data to characterize typical age-related signal intensity values limits evaluation. We sought to establish a range of age-dependent brain parenchymal signal intensity values on unenhanced T1WI in a sample of individuals (18 years of age or younger) with structurally normal brains.

MATERIALS AND METHODS

A single-center retrospective study was performed. Gadolinium-naïve pediatric patients with structurally normal MR brain imaging examination findings were analyzed (n = 114; 50% female; age range, 68 days to 18 years). ROI signal intensity measurements were obtained from the globus pallidus, thalamus, dentate nucleus, pons, and frontal lobe cortex and subcortical white matter. Multivariable linear regression was used to analyze the relationship between signal intensity values and age.

RESULTS

Results demonstrated a statistically significant association between signal intensity values and linear age in all neuroanatomic areas tested, except the frontal gray matter, (P < .01). There were no statistically significant differences attributable to patient sex.

CONCLUSIONS

Age-dependent signal intensity values were determined on unenhanced T1WI in structurally normal pediatric brains. Increased age correlated with increased signal intensity in all brain locations, except the frontal gray matter, irrespective of sex. The biologic mechanisms underlying our results remain unclear and may be related to chronologic changes in myelin density, synaptic density, and water content. Establishing age-dependent signal intensity parameters in the structurally normal pediatric brain will help clarify developmental aberrations and enhance gadolinium-deposition research by providing an improved understanding of the confounding effect of age.

Unstable blood sugar levels as triggers for the syndrome of acute bilateral basal ganglia lesions in diabetic uremia: Two Taiwanese patients with unusual neuroimaging findings

The syndrome of acute bilateral basal ganglia lesions in diabetic uremia is uncommon and usually affects Asian patients. The underlying pathogenesis of this syndrome is not clear. We searched PUBMED using the keywords “bilateral basal ganglia”, “diabetic”, and “uremia”, and found a total of 34 cases from 1998 to 2016. In most cases, blood sugar levels were normal. Here we report two Taiwanese cases presenting with dyskinesias. In one case the syndrome was triggered by hyperglycemia, and in the other by severe hypoglycemia. Their neuroimaging findings were unusual as compared with previously reported cases, presenting as mixed hypo- and hyperintensity on T1-weighted magnetic resonance imaging. We think these new finding would shed some light on the underlying pathophysiology of this syndrome. For treatment, it is advisable to keep glucose levels as stable as possible in diabetic uremic patients to prevent this syndrome. A rapid correction of hyper- or hypoglycemia after the onset may help recovery.

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Syndrome of acute bilateral basal ganglia lesions in diabetic uremia presenting with dyskinesias.

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Hyperglycemia and hypoglycemia can trigger this syndrome.

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Mixed hypo- and hyperintensity on T1-weighted MRI.

Syndrome of uremic encephalopathy and bilateral basal ganglia lesions in non-diabetic hemodialysis patient: a case report

BACKGROUND

Uremic encephalopathy (UE), a toxic metabolic encephalopathy, is an uncommon complication resulting from endogenous uremic toxins in patients with severe renal failure. UE syndrome can range from mild inattention to coma. The imaging findings of UE include cortical or subcortical involvement, basal ganglia involvement and white matter involvement. The basal ganglia type is uncommon, although previous cases have reported that Asian patients with diabetes mellitus (DM) are usually affected.

CASE PRESENTATION

A 32 year-old woman with a history of non-diabetic hemodialysis for 3 years suffered from severe involuntary movement, and brain magnetic resonance imaging showed symmetrical T2-weighted imaging (T2WI) and T2/fluid-attenuated inversion recovery (T2FLAIR) hyperintense nonhemorrhagic lesions in the bilateral basal ganglia. She was diagnosed with UE as syndrome of bilateral basal ganglia lesions, due to a combined effect of uremic toxins and hyperthyroidism. After treatment with high frequency and high flux dialysis, hyperbaric oxygen therapy and declining parathyroid hormone, the patient achieved complete remission with normal body movement and was discharged.

CONCLUSION

UE with basal ganglia involvement is uncommon, although generally seen in Asian patients with DM. Our case reported a hemodialysis patient that had non-diabetic UE with typical bilateral basal ganglia lesions, presenting with involuntary movement.

Bilateral pallidal hemorrhage in toxoplasmosis update of acute symmetric lesions of deep nuclei

As acute symmetric lesions of deep gray nuclei are often associated with an impaired level of consciousness and neuroimaging by itself cannot distinguish between etiologies, diagnosis may be problematic. Appreciation of the cause of the various neuroimaging patterns in conjunction with the history, examination and laboratory investigations allows for accurate diagnosis in the vast majority of cases. Given the metabolic vulnerability of deep gray nuclei, other than bi-thalamic infarction, it follows that toxic-metabolic and hypoxic-ischemic events account for the majority of cases. Nevertheless, the differential diagnosis is broad and diverse. We here describe two cases of bilateral pallidal hemorrhage in AIDS-associated toxoplasmosis, and review conditions recently described with acute symmetric deep gray nuclei lesions on neuroimaging.

Symmetric Basal Ganglia lesion in a diabetic dialysis patient: recurrence and pathogenesis

This paper describes a diabetic dialysis patient presenting two episodes of symmetric basal ganglia lesions occurring 18 months apart, and discusses the MR imaging findings and the pathogenesis of this condition.