P08.01 Immune-Related Acute Motor Axonal Neuropathy: A Small Case Series and Review of the Literature

BACKGROUND

Immunotherapy have revolutionized cancer treatment in the past decade, with a significant increased survival in patients with solid tumors. However, the use of immune checkpoint inhibitors (ICIs) has been associated with a growing number of neurotoxicities, some of which can be fatal if not recognized and treated promptly. Some of these neurotoxicities include very uncommon syndromes like Acute Motor Axonal Neuropathy (AMAN). Herein we present four oncological cases of patients who underwent immunotherapy and developed AMAN.

METHODS

Four patients were diagnosed with immune-related AMAN between 2017 and 2000 at H. Lee Moffitt Cancer Center. The patients were treated with standard of care and currently follow up in clinic.

RESULTS

We describe four oncological patients who developed a motor axonal neuropathy (i.e., AMAN) confirmed on nerve conduction studies following 2 cycles of immunotherapy, including a 28 year old woman with melanoma brain metastasis and a 50 year old woman with renal cell carcinoma both treated with ipilimumab and nivolumab, a 32 year old man with Hodgkin lymphoma who was treated with nivolumab and brentuximab, and a 77 year old woman with renal urothelial cancer who was treated with pembrolizumab and cabozantinib. All four patients were promptly recognized as having immune-related neurotoxicity (irNs), were promptly treated (i.e., high dose steroids +/- IVIG +/- other immunomodulators), and significantly improved and have remained stable.

CONCLUSION

This is the first case series of patients with AMAN following two cycles of immunotherapy, who were successfully treated. It is crucial to develop a better understanding of the irNs associated with ICIs, including those rare conditions that are difficult to diagnose and treat, as the utilization of these immunomodulating therapies continues to increase and expand to include other solid malignancies. Neurologists should be involved early on in any case of suspected irN to assist in the management of these complicated patients and a swift work up should be initiated for timely diagnosis and treatment.

Self-injury and incontinence in psychogenic seizures

Two patients who incurred significant injuries during psychogenic seizures prompted us to do a telephone survey of self-injury and incontinence in 102 consecutive patients diagnosed with psychogenic seizures by EEG-closed-circuit TV (EEG-CCTV) monitoring. Seventy-three patients (or a close family member or friend) were reached by telephone and responded to our survey. During typical attacks of psychogenic seizures, 40% reported injuries, 44% reporting tongue biting, and 44% reported urinary incontinence. Suicide attempts were reported by 32% and were more common in those with self-injury and urinary incontinence. We compared the results of patients with psychogenic seizures with those of 30 patients with refractory epilepsy documented by ictal recordings, using a similar telephone survey. Injuries of all types were more commonly reported by epilepsy patients. Burn injuries were reported only by patients with epilepsy. Suicide attempts were more commonly reported by the psychogenic seizure group. Self-injury and incontinence are commonly reported by psychogenic seizure patients. In view of their significant association with suicide attempts, they may indicate an underlying depression.

Differentiating clinical features of right and left temporal lobe seizures

We reviewed 127 seizures in 19 consecutive patients with temporal lobe epilepsy (TLE) documented by EEG/closed-circuit TV (EEG-CCTV) monitoring. Ten patients had seizure onset in the right temporal lobe (RTL, 54 seizures), and 9 had seizure onset in the left temporal lobe (LTL, 73 seizures). We compared the clinical characteristics in the two groups and analyzed the seizures for frequency of auras, seizures secondarily generalized, automatisms, tonic head deviation, focal posturing and jerking, ictal speech, and postical manifestations. Automatisms overall were more common in the RTL group, but individual categories (extremity, head and trunk, oroalimentary) were comparable among the two groups. Contralateral focal jerking and tonic head deviation were more common in LTL lobe seizures, as were secondarily generalized seizures. In addition to focal motor symptoms, three features were most statistically significant in distinguishing the two groups: Postictal aphasia occurred exclusively in the LTL group, whereas well-formed ictal speech and rapid return to baseline postictally were noted only in RTL seizures.