Toxic encephalopathy due to paradichlorobenzene toxicity: a case report and review of imaging characteristics

MRI features of neuronal intranuclear inclusion disease, combining visual and quantitative imaging investigations

OBJECTIVE

To observe the radiological characteristics of Neuronal Intranuclear Inclusion Disease (NIID) on lesion locations and diffusion property using quantitative imaging analysis.

METHODS

Visual inspection and quantitative analyses were performed on MRI data from 31 retrospectively included patients with NIID. Frequency heatmaps of lesion locations on T2WI and DWI were generated using voxel-wise analysis. Gray matter volume (GMV), white matter volume (WMV) and diffusion property of apparent diffusion coefficient (ADC) values of patients were voxel-wisely compared with healthy controls. Moreover, the ADC values within the DWI-detected lesion were compared with those within the adjacent cortical gray matter and white matter. Voxel-based lesion symptom mapping (VLSM) techniques, were used to determine the relationship between DWI lesion location and disease durations.

RESULTS

By visual inspection on the imaging findings, we proposed an "cockscomb flower sign" for describing the radiological feature of DWI hyperintensity within the corticomedullary junction. A "T2WI-DWI mismatch of spatial distribution" pattern was also revealed with visual inspection and frequency heatmaps, for describing the feature of a wider lesion distribution covering white matter shown on T2WI than that on DWI. Voxel-based morphometry comparison revealed that wildly reduced GMV and WMV, both the lesion areas detected by DWI and T2WI demonstrated ADC increase in patients. Furthermore, the ADC values within the DWI-detected lesion were intermediate between the adjacent cortex and the deep white matter with highest ADC. VLSM analysis revealed that frontal lobe, parietal lobe and internal capsule damage were associated with higher NIID durations.

CONCLUSION

NIID features with "cockscomb flower-like" DWI hyperintensity in area of corticomedullary junction, based on a "T2WI-DWI mismatch of spatial distribution" of lesion locations. The pathological substrate of corticomedullary junction hyperintensity on DWI, can not be explained as diffusion restriction. These typical radiological features of brain MRI would be helpful for diagnosis of NIID.

Two Cases Comparing the Presentations and Outcomes of Heroin-induced Toxic Leukoencephalopathy

Heroin-induced toxic leukoencephalopathy (TLE) is an uncommon condition that presents with nonspecific and variable neuropsychiatric findings. It may result in satisfactory recovery or death. Traditionally referred to as "chasing the dragon" syndrome and associated with inhalation of pyrolyzed heroin, recent publications have reported forms of the syndrome associated with noninhaled heroin. We report 2 cases of heroin-induced TLE associated with noninhaled routes of administration and a well-documented history of opioid use disorder. The patient in the first case presented with moderate to severe symptoms. Magnetic resonance imaging of the brain revealed increased T2 and fluid-attenuated inversion recovery signals bilaterally throughout subcortical and periventricular white matter. She survived with significant cognitive issues at discharge from which she adequately recovered by 11-month follow up. The patient in the second case presented with severe symptoms. Magnetic resonance imaging of the brain showed diffuse abnormal increased T2 and fluid-attenuated inversion recovery signals in the white matter of the centrum semiovale and corona radiata. The patient died within 3 weeks of presentation. Both cases illustrate the underrecognition of the form of TLE associated with noninhaled heroin and the difficulties involved in confirming recent heroin use that likely delayed the diagnosis. Further, noninhaled heroin-induced TLE can present with specific signs and symptoms that may help clinicians delineate it from the inhaled form. Given the ongoing opioid epidemic, early and accurate recognition of this condition is of paramount importance.

Mothball ingestion as a manifestation of pica, leading to paradichlorobenzene CNS toxicity

Background:

Pica is a poorly understood psychiatric disorder that presents with the ingestion of non-nutritious substances for unclear reasons. A high index of suspicion for unusual toxin exposure aids in the diagnosis of pica patients presenting with unexplained neurodegenerative features.

Methods:

We present a 47-year-old female with worsening gait over the past year. Prior to this, she was fully independent with activities of daily living, but is now mostly housebound due to frequent falls. Past medical history is significant for menorrhagia, iron deficiency anemia and pica. CBC and iron studies revealed iron deficiency with microcytic hypochromic anemia. MRI brain demonstrated symmetrical T2 hyperintensities within the middle cerebellar peduncles.

Results:

Differential diagnoses for her clinical deficits and imaging, including Spinocerebellar Ataxia, Multiple System Atrophy and Fragile X Tremor-Ataxia Syndrome, were excluded based on neurological assessment, family history and genetic PCR testing. Collateral history revealed a regular habit of mothball ingestion and serum paradichlorobenzene levels were elevated to 15mcg/mL. The patient was treated with iron replacement therapy and her symptoms gradually improved over several months.

Conclusion:

Iron deficiency anemia is commonly associated with pica, which can lead to toxin ingestion. A high index of suspicion for toxin ingestion in pica patients can immensely aid in the diagnosis. Mothball abuse secondary to pica may affect the CNS and can present with nonspecific neurodegenerative changes. To our knowledge, there have been no reported cases in the literature with paradichlorobenzene neurotoxicity predominantly affecting the middle cerebellar peduncles.

Detection rates, trends in and factors affecting observed levels of selected volatile organic compounds in blood among US adolescents and adults

Data from National Health and Nutrition Examination Survey were analyzed to evaluate detection rates, trend in and factors affecting the observed levels of 1,4-dichlorobenzene, benzene, ethylbenzene, o-xylene, styrene, toluene, and m/p-xylene among US adolescents and adults over 2005-2012. Over 2005-20102, among adolescents, detection rates declined by more than 50% for benzene, ethylbenzene, and o-xylene, and among adults, detection rates declined by more than 50% for ethylbenzene and o-xylene and by a little less than 50% for benzene. Among adults, adjusted levels of 1, 4-dichlorobenzene, benzene, ethylbenzene, o-xylene, toluene, and m/p-xylene decreased by 13.7%, 17.1%, 20%, 17.7%, 23.2%, and 18.7% respectively for every two-year survey cycle. Among adolescents, percentage decline in the levels of 1, 4-dichlorobenzene, benzene, ethylbenzene, o-xylene, styrene, toluene, and m/p-xylene was 15.2%, 21.4%, 19.3%, 16.1%, 47.8%, and 17.7% respectively for every two year survey period. The ratio of adjusted geometric means for adult smokers as compared to adult nonsmokers was 10.7 for benzene, 3.5 for ethylbenzene, 2.0 for o-xylene, 3.4 for styrene, 3.5 for toluene, and 2.2 for m/p-xylene. Among adolescents, gender did not affect the adjusted levels of any of the seven VOCs, and the order in which adjusted levels for 1, 4-dichlorobenzene by race/ethnicity was observed was: non-Hispanic white (0.038ng/mL)<Mexican American (0.102ng/mL)<non-Hispanic black (0.178ng/mL) and most of the pairwise comparisons were statistically significantly different (p<=0.02) but race/ethnicity did not affect the adjusted levels for benzene, ethylbenzene, o-xylene, styrene, toluene, and m/p-xylene. For benzene, males had lower levels of adjusted geometric means (AGM) than females (0.021 vs. 0.025ng/mL). For adults, gender did not affect the adjusted levels of 1, 4-dicholorobenzene, ethylbenzene, o-xylene, styrene, toluene, and m/p-xylene.