Bilateral basal ganglia lesions in patients with end-stage diabetic nephropathy (Brief Communication)

Magnetic Resonance Imaging in Uremic Encephalopathy: Identifying Key Imaging Patterns and Clinical Correlations

Background/Objectives: Magnetic Resonance Imaging (MRI) is essential in diagnosing neurological conditions, offering detailed insights into brain pathology. Uremic encephalopathy (UE) is a severe neurological disorder resulting from renal failure, characterized by cognitive impairments and brain abnormalities due to the accumulation of uremic toxins (UTs). Despite extensive research on UTs, there is a significant gap in the detailed characterization of MRI findings in UE patients. This study aims to bridge this gap by conducting a comprehensive literature review of cerebral MRI findings in UE. We hypothesize that specific MRI patterns correlate with the severity and clinical manifestations of UE, thereby enhancing diagnostic accuracy and improving patient outcomes. Methods: A literature review was performed using PubMed, Cochrane Library, and Google Scholar. The search terms included "uremic encephalopathy MRI", "uremia and kidney failure MRI", and "toxic and metabolic or acquired encephalopathies MRI". The inclusion criteria were original articles on UE and MRI findings published in English. Results: Common MRI sequences include T1-weighted, T2-weighted, FLAIR, and DWI. Frequent MRI findings in UE are cytotoxic and vasogenic brain edema in regions such as the basal ganglia and periventricular white matter. Patterns like the "lentiform fork sign" and basal ganglia involvement are key indicators of UE. Conclusions: MRI plays a crucial role in diagnosing UE by identifying characteristic brain edema and specific patterns. A comprehensive diagnostic approach, incorporating clinical, laboratory, and imaging data, is essential for accurate diagnosis and management. The study calls for larger well-designed cohorts with long-term follow-up to improve the understanding and treatment of UE.

The extrapyramidal syndromes of chronic kidney disease and dialysis (EPS-CKDD): diagnostic criteria, risk factors and prognosis

BACKGROUND

Acute extrapyramidal movement disorders in dialysis patients are rare, inconsistently defined and have uncertain aetiology and prognosis.

AIM

Define diagnostic criteria, prognosis and risk factors.

DESIGN AND METHODS

Retrospective case series review of 20 patients (14 female, mean age 62 years) receiving dialysis for a median of 15 (interquartile range 4-35) months who presented with acute parkinsonism (AP = 11) or chorea/athetosis (CA = 9).

RESULTS

All patients had type 2 diabetes (HbA1c 6.8 ± 1.0) and had received metformin. Lactic acidosis was present in 2 patients at presentation and serum lactate was elevated in 7/15 patients tested. No patient had abnormal copper or thyroid metabolism and 5/8 patients tested returned marginal abnormalities in heavy metal screening. Magnetic resonance imaging (MRI) revealed characteristic bilateral symmetric T2 hyperintensity of the basal ganglia (BG), predominantly putamen and globus pallidus (the lentiform nucleus) and more extensive involvement of the external and internal capsules in patients with AP presentation. Post-mortem demonstrated cytotoxic necrosis of the BG. Therapy included thiamine, intensive dialysis and cessation of metformin. Two patients died acutely, nine recovered and nine had residual symptoms. Median survival did not differ by presentation: AP 24 [95% confidence interval (CI) 21-27] and CA 33 (95% CI 32-35) months, P = 0.21.

CONCLUSIONS

There are two distinct clinical extrapyramidal movement disorders associated with specific diagnostic MRI imaging that support the diagnosis of the extrapyramidal syndromes of chronic kidney disease and dialysis. The associations with diabetes, metformin and metabolic acidosis suggest a common pathogenic mechanism but require additional study. Early recognition and treatment may improve outcomes.

Multiscale entropy and small-world network analysis in rs-fMRI - new tools to evaluate early basal ganglia dysfunction in diabetic peripheral neuropathy

OBJECTIVE

The risk of falling increases in diabetic peripheral neuropathy (DPN) patients. As a central part, Basal ganglia play an important role in motor and balance control, but whether its involvement in DPN is unclear.

METHODS

Ten patients with confirmed DPN, ten diabetes patients without DPN, and ten healthy age-matched controls(HC) were recruited to undergo magnetic resonance imaging(MRI) to assess brain structure and zone adaptability. Multiscale entropy and small-world network analysis were then used to assess the complexity of the hemodynamic response signal, reflecting the adaptability of the basal ganglia.

RESULTS

There was no significant difference in brain structure among the three groups, except the duration of diabetes in DPN patients was longer (p < 0.05). The complexity of basal ganglia was significantly decreased in the DPN group compared with the non-DPN and HC group (p < 0.05), which suggested their poor adaptability.

CONCLUSION

In the sensorimotor loop, peripheral and early central nervous lesions exist simultaneously in DPN patients. Multiscale Entropy and Small-world Network Analysis could detect basal ganglia dysfunction prior to structural changes in MRI, potentially valuable tools for early non-invasive screening and follow-up.

Movement Disorders Due to Selective Basal Ganglia Lesions with Uremia

BACKGROUND

Basal ganglia (BG) lesions are rarely reported in patients with uremia and may manifest by movement disorders. However, their exact incidence and pathogenesis have not been extensively studied. This study aimed to determine the frequency, types, risk variables (clinical, laboratory, and imaging), and manifestations of BG lesions with uremia and patients' neurologic outcomes.

METHODS

This observational study included 70 adults (mean age: 45.87 ± 3.36 years; duration of uremia: 5.5 ± 1.5 years). They underwent extensive evaluations (clinical, laboratory, and neuroimaging) and had prospectively evaluated clinically every 3 months for 2 years. Repeated magnetic resonance imaging (MRI) brains were done to patients with movement disorders and correlated with their neurologic outcomes.

RESULTS

BG lesions were found in 15 patients (21.4%) and 6 (8.6%) had movement disorders [Parkinsonism (n = 4), choreo-dystonia (n = 1) and dystonia (n = 1)] after the onset of uremia (mean = 10 months). There were no characteristic risk variables that distinguished patients with movement disorders from those without. Five developed movement disorders prior to the period of the study and one was de novo. The majority was females and had diabetes and higher frequencies of abnormal renal dysfunction, metabolic derangements, and white matter hyperintensities in MRIs. Movement disorders persisted in all patients despite the resolution of neuroimaging in three patients.

CONCLUSIONS

There is no clear threshold for renal failure to result in movement disorders due to BG lesions. The clinical outcome is variables depending on each patient's comorbidities and complications. Persistent neuronal damage (due to uremic toxins/metabolic/nutritional and ischemic/microvascular factors) has been suggested as the cause of poor neurologic outcomes.

Large-Scale Neuronal Network Dysfunction in Diabetic Retinopathy

Diabetic retinopathy (DR) patients are at an increased risk of cognitive decline and dementia. There is accumulating evidence that specific functional and structural architecture changes in the brain are related to cognitive impairment in DR patients. However, little is known regarding whether the functional architecture of resting-state networks (RSNs) changes in DR patients. The purpose of this study was to investigate the intranetwork functional connectivity (FC) and functional network connectivity (FNC) of RSN changes in DR patients using independent component analysis (ICA). Thirty-four DR patients (18 men and 16 women; mean age, 53.53 ± 8.67 years) and 38 nondiabetic healthy controls (HCs) (15 men and 23 women; mean age, 48.63 ± 11.83 years), closely matched for age, sex, and education, underwent resting-state magnetic resonance imaging scans. ICA was applied to extract the nine RSNs. Then, two-sample t-tests were conducted to investigate different intranetwork FCs within nine RSNs between the two groups. The FNC toolbox was used to assess interactions among RSNs. Pearson correlation analysis was conducted to explore the relationship between intranetwork FCs and clinical variables in the DR group. A receiver operating characteristic (ROC) curve was conducted to assess the ability of the intranetwork FCs of RSNs in discriminating between the two groups. Compared to the HC group, DR patients showed significant decreased intranetwork FCs within the basal ganglia network (BGN), visual network (VN), ventral default mode network (vDMN), right executive control network (rECN), salience network (SN), left executive control network (lECN), auditory network (AN), and dorsal default mode network (dDMN). In addition, FNC analysis showed increased VN-BGN, VN-vDMN, VN-dDMN, vDMN-lECN, SN-BGN, lECN-dDMN, and AN-BGN FNCs in the DR group, relative to the HC group. Furthermore, altered intranetwork FCs of RSNs were significantly correlated with the glycosylated hemoglobin (HbA1c) level in DR patients. A ROC curve showed that these specific intranetwork FCs of RSNs discriminated between the two groups with a high degree of sensitivity and specificity. Our study highlighted that DR patients had widespread deficits in both low-level perceptual and higher-order cognitive networks. Our results offer important insights into the neural mechanisms of visual loss and cognitive decline in DR patients.

Chronic renal dysfunction, proteinuria, and risk of Parkinson's disease in the elderly

BACKGROUND

The roles of chronic kidney disease and proteinuria in the development of Parkinson's disease have not been widely studied. The objective of this study was to examine the associations of chronic renal dysfunction and proteinuria with the risk of PD in older adults using cohort data of the whole South Korean population.

METHODS

We included 3,580,435 individuals aged ≥65 years who had undergone health checkups provided by the National Health Insurance Service of South Korea between 2009 and 2012 and were followed until 2015. Multivariable Cox proportional hazards regression models were performed.

RESULTS

During a mean follow-up of 5.2 ± 1.3 years, 30,813 individuals (0.86% of the total population) developed PD. Lower estimated glomerular filtration rate and a higher degree of proteinuria on a dipstick test were associated with higher incidence probability of PD (log-rank P < 0.001). In Cox regression models, chronic renal dysfunction graded by estimated glomerular filtration rate (mL/min/1.73 m² ) was associated with increased risk of PD after adjusting for potential confounding variables; hazard ratio (95% confidence interval) was 1.13 (1.10-1.17) for estimated glomerular filtration rate 60-90, 1.36 (1.31-1.42) for estimated glomerular filtration rate 30-60, and 1.47 (1.32-1.63) for estimated glomerular filtration rate <30 (P for trend <0.001). Proteinuria ≥1+ was also associated with increased risk of PD development (hazard ratio, 1.12; 95% confidence interval, 1.06-1.18). Coexistence of chronic kidney disease and proteinuria showed an increased hazard ratio of 1.33 (95% confidence interval, 1.23-1.45) for PD occurrence.

CONCLUSIONS

Our findings suggest that chronic renal dysfunction and dipstick-positive proteinuria may be independent risk factors for the development of PD in older adults. © 2019 International Parkinson and Movement Disorder Society.

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.

MRI Findings of Syndrome of Acute Bilateral Symmetrical Basal Ganglia Lesions in Diabetic Uremia: A Case Report and Literature Review

The syndrome of acute bilateral basal ganglia lesions is an uncommon clinical occurrence exhibiting acute onset of movement abnormalities, which can be seen almost exclusively among patients with chronic renal failure, especially in the setting of concurrent diabetes mellitus. Symmetrical lesions located in basal ganglia demonstrated in MRI are typical manifestation of this syndrome. Our study includes routine MRI examination, MRS, 3D-ASL, and SWI findings, which have been rarely reported and will contribute to diagnosing more cases about this syndrome.

Decreased dopamine transporter and receptor ligand binding in Parkinsonism with diabetic uremic syndrome

Here, we describe the case of a 47-year-old man with bilateral striatal lesions with diabetic uremia. Following 4 years of hemodialysis, the patient experienced sudden onset of rigidity, bradykinesia, gait disorder, and postural instability. Symptoms were remediated 2 months later, and were no longer responsive to levodopa approximately 1 year after the onset. Brain magnetic resonance imaging (MRI) during the acute phase showed T 2-weighted high signal edematous lesions in the bilateral striatum, subsequently developing into vacuolated lesions. A positron emission tomography (PET) scan using ((11)C)-labeled 2-carbomethoxy-3-(4-fluorophenyl) tropane [((11)C) CFT] and ((11)C)-labeled raclopride [((11)C) RAC] revealed significant decreases bilaterally in pre- and postsynaptic functions of the dopaminergic neurons. When we experience a case with bilateral putaminal destruction resulting in Parkinsonism, examination of the function of doperminergic neurons and dopamine receptors using molecular imaging is useful to predict levodopa response and prognosis.

Brain SPECT and MRI Findings in a Uremic Patient With Parkinsonism

Parkinsonism associated with basal ganglia pathology represents a rare complication in uremia patients, characterized by acute hyperkinetic or hypokinetic extrapyramidal movement disorders. We herein present brain SPECT and MR findings of uremic patients with end-stage renal failure exhibiting parkinsonian symptoms. The bilateral basal ganglia exhibited decreased uptake on SPECT, and abnormal signals on MR, suggesting pathology.

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.

Chorea due to diabetic hyperglycemia and uremia: distinct clinical and imaging features

This study was undertaken to describe the clinical and imaging characteristics of patients with chorea associated with nonketotic hyperglycemia (C-NKH) in comparison with patients with chorea associated with uremia (C-URE). We retrospectively analyzed the clinical data of consecutive 10 C-NKH and five C-URE patients who were treated between January 1, 2001 and January 31, 2013. Women were more frequently affected by C-NKH (70% vs. 30%) and C-URE (80% vs. 20%) compared with men. The C-NKH patients demonstrated T1-hyperintense and inhomogeneous lesions in the basal ganglia, whereas C-URE patients demonstrated T2-hyperintense and homogeneous lesions in the basal ganglia. The mean time for chorea resolution after treatment was significantly shorter in C-NKH patients than in C-URE patients (4.4 ± 2.6 d vs. 73.8 ± 14.2 d, respectively; P = 0.005). The clinical and imaging features are remarkably different between C-NKH and C-URE patients, suggesting distinct pathogenic mechanisms.

Rare case of reversible acute symmetrical lesions of the bilateral Basal Ganglia associated with diabetic nephropathy and chronic renal failure

Reversible acute symmetrical basal ganglial lesion on magnetic resonance imaging and/or computed tomography in cases of diabetic nephropathy and chronic renal failure exhibiting acute onset of movement abnormalities like chorea is a very rare entity. It has characteristic clinical and imaging features. Only 29 cases are described in the literature, including the current one. These cases are predominantly Asian patients from the Far East and only one Asian Indian patient has been described. We report the second Asian Indian case of this condition and describe its various clinical and imaging features. Our aim is to educate the clinicians and radiologists about this condition, so that more such cases can be detected.

Lentiform fork sign: a magnetic resonance finding in a case of acute metabolic acidosis

We report a 33 year-old woman addicted to chronic unspecified solvents abuse with stupor, respiratory disorders, tetraplegia and severe metabolic acidosis. On admission an unenhanced cranial CT scan showed symmetrical hypodensities of both lentiform nuclei. MR imaging performed 12 hours after stupor demonstrates bilateral putaminal hemorrhagic necrosis, bilateral external capsule, corona radiata and deep cerebellar hyperintensities with right cingulate cortex involvement. DWI reflected bilateral putaminal hyperintensities with restricted water diffusion as to citotoxic edema and development of vasogenic edema in the external capsule recalling a fork. On day twenty, after specific treatments MRI demonstrated a bilateral putaminal marginal enhancement. Bilateral putaminal necrosis is a characteristic but non-specific radiological finding of methanol poisoning. Lentiform Fork sign is a rare MRI finding reported in literature in 22 patients with various conditions characterized by metabolic acidosis. Vasogenic edema may be due to the differences in metabolic vulnerability between neurons and astrocytes. We postulate that metabolic acidosis could have an important role to generate this sign.

Increased risk of Parkinson's disease in patients with end-stage renal disease: a retrospective cohort study

BACKGROUND

Studies on dyskinesia and Parkinson's syndrome associated with chronic kidney disease or end-stage renal disease (ESRD) have been mainly limited to case reports or case series studies. This population-based study investigated the risk of Parkinson's disease in patients with ESRD.

METHODS

From a universal insurance claims database of Taiwan, we established a cohort of 8,325 adults with newly diagnosed ESRD from 1997 to 2010 without a history of Parkinson's disease. A control cohort of 33,382 insured subjects without a history of kidney disease or Parkinson's disease was also selected, with frequency matched for age, sex and index date of the patients with ESRD. Both cohorts were followed up until the end of 2010.

RESULTS

The Parkinson's disease incidence was 1.55-fold higher in the cohort with ESRD than in the comparison cohort (48.8 vs. 31.7 per 10,000 person-years) with an adjusted hazard ratio of 1.73 (95% confidence interval, 1.39-2.15). Sex-specific and age-specific analysis showed a higher relative risk for women and younger patients with ESRD compared to the control cohort.

CONCLUSIONS

ESRD is significantly associated with an increased risk of Parkinson's disease. Close surveillance for Parkinson's disease should be considered for patients with ESRD.

Diabetic uremic syndrome studied with cerebral MR spectroscopy and CT perfusion

Diabetic uremic syndrome (DUS) is an increasingly reported acute neurometabolic cerebral disease with characteristic clinical and imaging features. Clinical spectrum includes a wide range of movement disorders such as acute parkinsonism. Imaging studies show reversible (with hemodialysis) bilateral lesions in the lenticular nuclei. DUS pathophysiology has not been entirely clarified yet. Our case study shows certainly that LN lesions are characterized with increased lactate peak with MR spectroscopy and decreased perfusion in computerized tomography perfusion along with increased diffusion with apparent diffusion coefficient (ADC) mapping in the subacute phase of the syndrome. Abnormalities were almost normalized quickly after metabolic control by hemodialysis. Together with reports indicating that a deficit of glucose use exacerbated with acute increase of uremic toxins in bilateral LN, observed changes (lactate peak and hypoperfusion) led us to state that a primary metabolic depression may cause this syndrome. Metabolic depression is probably due to uncompensated uremic toxin accumulation related mitochondrial supression and/or dysfunction. This definition fits well to the other elements of DUS such as ADC evolution and marked lesion regression. Our single case study is not supportive of other previously credited mechanisms such as microvascular dysfunction related focal ischemia or hypoperfusion, prolonged uremic toxin related histotoxic hypoxia, central pontine myelinolysis-like demyelination and posterior leukoencephalopathy spectrum disorder related vasogenic edema.

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

A rare syndrome of acute symmetrical bilateral basal ganglia lesions in diabetic dialysis patients that manifests clinically with headache, dysarthria, and gait and movement disorder has been described almost exclusively in patients of Asian descent. The pathophysiology of this condition has not been established. Of the 28 cases reported, 3 patients have been from North America. In the context of magnetic resonance imaging showing dramatic resolution of lesions of the basal ganglia, this report describes a fourth case from North America of a 47-year-old Hispanic woman with diabetes on dialysis therapy who presented with headache, unsteady gait, and slurred speech. We also consider presymptomatic metabolic abnormalities in the pathogenesis of this disease.

[A case of subacute parkinsonism presenting as bilateral basal ganglia legions by MRI in diabetic uremic syndrome]

A 60-year-old male was admitted because he had developed tremulous movement in both upper and lower limbs and gait disturbance over the course of 3 months. He had been on continuous ambulatory peritoneal dialysis almost 1 year earlier due to end-stage diabetic nephropathy. A neurological examination revealed a mild disturbance of his consciousness, asterixis in the upper limbs, bilateral extensor plantar responses and parkinsonism, which were characterized by bradykinesia, akinesia, rigidity, and bilaterally tremors at rest. Cranial magnetic resonance imaging (MRI) revealed swollen bilateral basal ganglia legions, which appeared hyperintense on T2-weighted images. The patient was treated for metabolic acidosis and continued hemodialysis three times a week; however, the parkinsonism remained 1 year later. Follow-up MRI revealed decreased swelling of the basal ganglia, and the pattern of diffusion-weighted images and the apparent diffusion coefficient (ADC) map indicated vasogenic and cytotoxic edema in bilateral globus pallidus. The case was diagnosed as encephalopathy due to diabetic uremic syndrome, initially characterized by Wang et al. (2003). Only 17 cases with parkinsonism have been reported. Diabetic uremic syndrome is characterized by acute or subacute onset consciousness disturbance and movement disorders such as parkinsonism, chorea and the other extrapyramidal signs to various degrees related to bilateral lesions of the basal ganglia.

Reversible acute parkinsonism and bilateral Basal Ganglia lesions in a diabetic uremic patient

The syndrome of bilateral basal ganglia lesions in diabetic uremic patients is a rare disorder mostly reported in Asians. There are few reports of the syndrome in Caucasians. It manifests as an acute hyperkinetic or hypokinetic extrapyramidal disorder in association with uniform neuroimaging findings of bilateral symmetrical basal ganglia changes in diabetics undergoing hemodialysis. Its pathophysiology remains largely unknown. Thus, we report a typical case of the syndrome in a Caucasian patient who developed an acute and reversible akinetic rigid parkinsonism secondary to bilateral basal ganglia lesions.

Movement disorders in patients with diabetes mellitus

Movement disorders are not infrequent in patients with diabetes mellitus. These may occur on the basis of both central and peripheral nervous system dysfunction and can be secondary to severe hyperglycemia, complications of diabetes or its treatment and less often to diseases in which both diabetes and a movement disorder are primary manifestations of the same underlying disease. We present a typical case of a severe movement disorder complicating diabetes as a springboard to review the spectrum of disorders associated with this condition.

Acute movement disorder with bilateral basal ganglia lesions in diabetic uremia

Acute movement disorder associated with symmetrical basal ganglia lesions occurring in the background of diabetic end stage renal disease is a recently described condition. It has distinct clinico-radiological features and is commonly described in Asian patients. We report the first Indian case report of this potentially reversible condition and discuss its various clinico-radiological aspects.

Fulminant encephalopathy with basal ganglia hyperintensities in HIV-infected drug users

OBJECTIVE

To define a clinical syndrome associated with active drug abuse in HIV-infected individuals.

METHODS

We performed a retrospective review to identify individuals treated at the Johns Hopkins Hospital from 1993 to 2008 who were HIV-infected and were actively abusing drugs and had bilateral basal ganglia lesions on MRI. They were identified using a key word search in the radiology database, autopsy database, and the Moore HIV clinic database. Clinical, laboratory, and radiographic findings were correlated to define the syndrome.

RESULTS

Ten individuals were identified who presented with a change in mental status or seizures, used cocaine or cocaine with heroin, had uncontrolled HIV infection (>190,000 copies/mL of plasma), elevated CSF protein (63-313 mg/dL), and diffuse hyperintense bilateral basal ganglia lesions on imaging. The majority of patients (8/10) had renal failure and despite supportive therapy most (7/9) ultimately died (median survival 21 days). Postmortem examination in one individual showed the presence of overwhelming microglial activation in the basal ganglia. The 2 surviving individuals were started on combined antiretroviral therapy (CART) during hospitalization.

CONCLUSION

We describe a unique clinical syndrome of a fulminant encephalopathy associated with primarily basal ganglia involvement in HIV-infected drug abusers. This syndrome is a rare but serious condition that is associated with a high mortality rate. Early CART institution may be useful and neuroprotective in this disorder, although this requires further investigation.

Hypoglycemia as a trigger for the syndrome of acute bilateral basal ganglia lesions in uremia

The syndrome of acute bilateral basal ganglia lesions is a rarely described complication of uremia occurring typically in the setting of concurrent long-standing diabetes mellitus. Reversible symmetrical lesions located in basal ganglia found on brain magnetic resonance imaging are hallmarks of this syndrome. Clinical presentation includes parkinsonism and/or involuntary movements. The cause of this syndrome is largely unknown. Among the factors that are believed to contribute to its pathogenesis are uremic toxins, metabolic acidosis and diabetic microangiopathy. Here we report a patient with uremia and newly diagnosed diabetes, who developed the syndrome of acute bilateral basal ganglia lesions after an incidence of severe hypoglycemia induced by oral hypoglycemic agents. We consider hypoglycemia as a candidate trigger factor for the syndrome of acute bilateral basal ganglia lesions and highlight the importance of strict glucose control in uremic patients.

Lentiform Fork sign: a unique MRI picture. Is metabolic acidosis responsible?

BACKGROUND AND PURPOSE

Bilateral basal ganglia lesions are neither diagnostic nor pathognomonic of uremic encephalopathy (UE). Nonetheless, bilateral basal ganglia T2/FLAIR hyperintensities have been widely reported to be associated with UE. The aim of this study was to describe a unique neuroradiological sign seen on the MRI brain in UE, present a retrospective chart review of patients with UE over the past 10 years for evidence of similar MRI appearance, review literature for evidence of this sign, and generate a hypothesis to explain its pathophysiological basis.

METHODS

We describe a previously unreported and unique MRI picture, the Lentiform Fork sign, in a patient with UE. We conducted a focused retrospective chart review of patients with UE over the past 10 years, for evidence of similar MRI changes. We review literature (through PUBMED, OVID, and CENTRAL) for evidence of this sign and propose a hypothesis to explain the basis of this MRI sign.

RESULTS

We describe the Lentiform Fork sign in a patient with UE. Of our 21 retrospectively reviewed patients with UE who underwent MRI, only one had this sign. Literature review identified 22 patients with this sign who had various conditions, all associated with metabolic acidosis. Fourteen of these patients had documented evidence of severe metabolic acidosis. We propose the hypothesis that metabolic acidosis is the basis of this Lentiform Fork sign.

CONCLUSION

Lentiform Fork sign is a unique, previously unreported MRI picture that is seen not only in patients with UE but also in other conditions that result in metabolic acidosis, helping discriminate a specific etiology from the myriad of conditions that are lumped under the rubric of "basal ganglia hyperintensity." We propose the hypothesis that metabolic acidosis may be the key factor in the pathogenesis of this sign.

Acute extrapyramidal disorder with bilateral reversible basal ganglia lesions in a diabetic uremic patient: diffusion-weighted imaging and spectroscopy findings

Acute movement disorders associated with bilateral lesions in the basal ganglia are increasingly described in patients affected by diabetes and uremia. Pathophysiology has not been utterly understood yet, but it is likely to be multifactorial, with both ischemic/microvascular and metabolic/toxic factors determining the lesions and symptoms. We have studied a uremic diabetic patient who was admitted in emergency after presenting choreic movements, in which CT and MR, including diffusion-weighted imaging and spectroscopy, showed bilateral symmetric basal ganglia lesions with regression at follow-up. This is the first report in the literature describing spectroscopic findings in this condition.