In this didactic, we will cover the emergent management of intrathecal baclofen therapy including baclofen overdose and baclofen withdrawal. I am Andrea Toomer, a physiatrist with the Colicchia Neurological Clinic and the LSU Department of Neurosurgery. I am a speaker and an advisor for a number of pharmaceutical and device companies. We will be reviewing the clinical signs and symptoms of baclofen overdose and baclofen withdrawal. We will be discussing the differential diagnosis in patients who present with signs consistent with overdose or withdrawal. We will outline the management of baclofen withdrawal and we will review the treatment protocol for baclofen overdose. When we are evaluating patients for potential baclofen overdose or baclofen withdrawal, it is important to perform a thorough history and physical examination. We should be evaluating for other causes of increased spasticity or other causes of mental status changes. There are many other medical conditions that can cause an increase in spasticity. Additionally, there are many medical situations that can cause mental status changes. We should not be too quick to blame intrathecal baclofen as the cause of the increased spasticity or the mental status change. Of course, baclofen overdose and baclofen withdrawal will always remain in the differential for a patient who has a baclofen pump. But we should also be considering other diagnoses such as sepsis, meningitis, autonomic dysreflexia, bladder retention, urinary tract infection, and constipation. These diagnoses, as well as many others, can cause increases in spasticity and can cause mental status changes and should always be considered. When evaluating for baclofen overdose or baclofen withdrawal, we should perform a thorough evaluation of the pump system itself. We should interrogate the pump, looking for any programming errors and determining if any alarms have occurred. We should evaluate the logs to ensure that no motor stalls have occurred in the pump. We can also access the reservoir of the pump and aspirate medication. This would allow us to determine if there are any volume discrepancies between the actual residual volume and the estimated residual volume. By accessing the pump, we can also remove medication, which may be of benefit in the case of potential baclofen overdose. We can also perform a catheter access port aspiration. By aspirating through the catheter access port, this allows us to determine if the catheter is patent and has easy flow of CSF. We can also remove medication and aspirate further CSF through the catheter access port aspiration. This may be of benefit with potential baclofen overdose. It is important to recognize the symptoms of baclofen withdrawal. We can see exaggerated rebound spasticity, rigidity, labile blood pressure, mental status changes, including agitation, anxiety, hallucinations, and severe itching without an evident rash. Baclofen withdrawal can progress to multi-organ system failure, rhabdo, coma, and death. It is therefore very important to quickly identify the signs of baclofen withdrawal and treat appropriately. Treatment for baclofen withdrawal requires that the patient be admitted and monitored in either the acute care hospital or the ICU setting, depending on the severity of the baclofen withdrawal symptoms. We can use both oral and IV medications as temporizing measures to treat the withdrawal symptoms. We can use oral baclofen as well as oral and IV benzodiazepines to treat the symptoms of withdrawal. The ultimate treatment is to resume intrathecal baclofen therapy. Depending on the cause of the baclofen withdrawal, we may need to bring the patient back for a catheter revision or a catheter replacement in order to permanently reinstitute intrathecal baclofen therapy. As a short-term temporizing measure, we can also bolus baclofen through a lumbar puncture. All of these measures will help to lessen the severity of baclofen withdrawal, but again, the ultimate treatment is to resume intrathecal baclofen therapy. Symptoms of baclofen overdose include nausea, vomiting, dizziness, respiratory depression, hypothermia, progression of hypotonia in a rostral pattern, somnolence. This can advance to seizures and coma requiring ventilatory support if not recognized and treated appropriately. When treating baclofen overdose, we first manage our ABCs. Intubation and ventilatory support may be necessary depending on the severity of baclofen overdose. We want to reduce and or completely interrupt the delivery of intrathecal baclofen into the spinal fluid. We can do this by programming the pump to lower the dose or stop the dose. We can empty the pump reservoir so that there is no further baclofen that can be delivered through the catheter into the intrathecal space. We can also drain spinal fluid through a catheter access port aspiration or through a lumbar puncture. By removing CSF, we are also removing some of the intrathecal baclofen that has been delivered. This method can help to reduce the symptoms of baclofen overdose. A 14-year-old male with cerebral palsy and spasticity presents to the emergency room. His mother reports that he recently had an intrathecal baclofen pump implanted and he was started at a dose of 100 micrograms per day. She reports that his pump was interrogated earlier that day and his dosing was changed. He began to show signs of somnolence within an hour or two of that visit. On exam, you note that he is difficult to arouse and he has hypotonia in both legs. A pump interrogation shows that his dose is programmed at 1,125 micrograms per day. Appropriate treatment includes all of the following except A. Catheter access port aspiration B. Pump interrogation and dosing change to minimum rate C. Admission to the ICU for close observation D. Initiation of IV benzodiazepines In this clinical scenario, the patient is clearly demonstrating signs of baclofen overdose due to a programming error. The patient should be admitted for close observation and preparations should be made to support airway breathing and circulation should his condition worsen. The pump should be interrogated and the programming should be changed to interrupt further delivery of intrathecal baclofen. Catheter access port access and drainage would remove the baclofen from the catheter and remove some of the baclofen that has been delivered into the cerebrospinal fluid. IV benzodiazepines are in the treatment algorithm for intrathecal baclofen withdrawal, not for intrathecal baclofen overdose. In summary, baclofen overdose and baclofen withdrawal are rare but serious complications of intrathecal baclofen therapy. A thorough history and physical examination must be performed to create a differential diagnosis and initiate the appropriate treatment. Resumption of intrathecal baclofen therapy is the ultimate treatment for intrathecal baclofen withdrawal. Temporizing measures with oral baclofen and oral or IV benzodiazepines can lessen symptoms. Supportive care and reduction or interruption of intrathecal baclofen therapy is the treatment for intrathecal baclofen overdose.

intrathecal baclofen

baclofen overdose

baclofen withdrawal

spasticity management

pump system evaluation