Abhishek Shrinet, MD
Resident Physician
Temple University Hospital
Philadelphia, Pennsylvania, United States
Jonathan Arias, DO
Resident Physician
Temple University Hospital
Allentown, Pennsylvania, United States
Ayan N. Ahmed, MD
Resident Physician
Temple University Hospital
Sewickley, Pennsylvania, United States
Norberto Escobales, MD
Resident Physician
Temple University Hospital
Philadelphia, Pennsylvania, United States
Maitland B. Wiren, DO
Resident Physician
Temple University Hospital
Philadelphia, Pennsylvania, United States
A 16-year-old male with a complex psychiatric history on multiple psychotropic medications presented following a pedestrian versus vehicle collision, resulting in severe TBI. During admission, he developed autonomic instability, hypertonia, rigidity, ocular clonus, and agitation, initially attributed to TBI and PSH. His symptoms were refractory to standard management, prompting consideration of serotonin syndrome and NMS, though overlapping criteria and confounding symptoms from TBI and PSH complicated diagnosis. Initial assessment suggested serotonin syndrome, leading to discontinuation of all psychotropic agents; however, as his condition worsened, he was ultimately diagnosed with NMS. Given his recent TBI, amantadine pharmacotherapy was selected over conventional bromocriptine for its neuroprotective effects via NMDA antagonism. Within two weeks, his NMS resolved and he showed significant cognitive and functional recovery. This case illustrates the diagnostic challenges between serotonin syndrome and NMS in TBI patients with PSH. In such cases, amantadine offers a multifaceted approach, addressing both NMS and TBI through its dopaminergic effects and NMDA antagonism.
Discussions: TBIs can disrupt dopaminergic pathways of the brain, heightening the risk for NMS which is fatal in 20% of cases. Although NMS criteria are well defined, it may be misdiagnosed as serotonin syndrome due to shared features such as autonomic dysfunction and agitation. Furthermore, PSH, which occurs in almost 30% of moderate to severe TBI patients, can further obscure the clinical picture leading to a delay in appropriate diagnosis and management. Once NMS is diagnosed, bromocriptine is typically first-line pharmacotherapy, though amantadine may have greater utility in TBI patients suffering from PSH and NMS due to its effects on neuromuscular rigidity, agitation, and neuroprotection.
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