Objective:

To report a case of baclofen overdose with favorable recovery despite prolonged coma and transient absence of brainstem reflexes and reversible loss of cortical somatosensory evoked potentials (SSEP). 

Background:

Intoxication with baclofen, a selective GABA-B receptor agonist, can produce coma, seizures, and respiratory depression. Brainstem function may be abolished in the most severe cases. However, to our knowledge, transient loss of cortical responses on SSEP has not been previously described.

Design/Methods:

NA

Results:

A 76 year-old female presented with PEA arrest after baclofen and tramadol overdose. Return of spontaneous circulation was achieved after prolonged resuscitation. In the Emergency Department, she had absent brain stem reflexes with fixed, dilated pupils and no motor response to pain.  Continuous EEG displayed burst-suppression evolving into non-convulsive status epilepticus.  Seizures were controlled with aggressive anti-seizure therapy. SSEP testing on day 3 showed markedly reduced cortical (N20) response on the left and absent response on the right. MRI demonstrated restricted diffusion in bilateral hippocampi and basal ganglia. Repeat SSEP on day 5 showed normal N20 responses bilaterally. Repeat MRI on day 7 showed minimal residual signal changes on FLAIR. By day 11, the patient was following commands. She was discharged on day 30 with mild and improving cognitive deficits.

Conclusions:

Baclofen can result in prolonged coma with temporary absence of brainstem reflexes. This case shows that reversible loss of cortical SSEPs is also possible. Prognostication in comatose patients with baclofen overdose should therefore be performed with extreme caution. Serial testing of SSEPs may be advisable in cases in which cortical responses are initially absent.