The MRI brain study is approximately 9 months post the initial event and presentation to an external facility. The initial CT brain at the time of presentation is unremarkable. The patient confirmed pesticide self-ingestion during a suicide attempt. Delayed MRI brain demonstrates features consistent with chronic sequela of a confirmed organophosphate poisoning with bilateral and symmetric caudate nuclei and putaminal infarction.

Organophosphate poisoning predominantly affects the putamina and caudate nuclei and MRI studies during the intermediate phase are positive and demonstrate a low T1 signal, and high T2/FLAIR signal with the associated restriction on diffusion imaging and corresponding reduced average diffusivity on ADC mapping. In general, the signal alterations are meant to fully resolve over an unspecified period ranging from weeks to months. In this instance, the patient remains symptomatic 9 months after the event, with severe polyneuropathy and generalized limb weakness affecting daily activities. It is uncertain if clinical and MRI improvement will occur.

Increased T1 signal is usually due to calcification, TPN or chronic liver disease/ manganese toxicity⁴. In addition, it may be due to cellular swelling with mitochondrial dysfunction⁵ or due to the presence of swollen astrocytes (called gemistocytes) at the sites of insult⁶. In this instance, the high T1 signal may represent a combination of the above causes.