Neurosurgeon Advises on Radiation Procedure for Trigeminal Neuralgia

A neurosurgery expert witness opines on a case involving a patient who was left with chronic pain following a dental procedures and linear accelerator radiation therapy for trigeminal neuralgia. This case involves a fifty-eight-year-old female patient with no significant past medical history who presented to her dentist complaining of pain in the right jaw line and cheek bone region. The pain was originally thought to be from an infected tooth which prompted an extraction by a dentist.When the extraction failed to relieve the patient’s pain she was referred to an oral surgeon by the treating dentist for the removal of a second tooth which was now believed to be the source of the pain. Before the procedure a CT head was performed and read as normal with no masses or lesions present.

Following the second extraction, the patient’s pain became exponentially worse necessitating a neurology consultation. After many visits the patient was finally diagnosed with trigeminal neuralgia. A neurologist recommended that a trigeminal nerve block be performed. The treatment had limited success and the patient continued to experience breakthrough pain despite the nerve block. The patient was then referred to a neurosurgeon who suggested that the patient receive LINAC (linear accelerator) radiation therapy to ablate the trigeminal nerve root. Following surgery the symptoms only worsened further and the patient decompensated neurologically due to radiation necrosis. The patient now displays continued facial pain, stroke-like drooping of the left side of her face, and difficulty walking; she has needed numerous costly additional procedures, and has needed to undergo locomotor training in an attempt to regain her balance and full ability to walk.

Question(s) For Expert Witness

Is it within the standard of care to use this linear acceleration radiation to treat trigeminal neuralgia?

Expert Witness Response

Stereotactic radiation is one of the standard treatments for trigeminal neuralgia. About 75% of patients receive initial pain relief and around 50% of patients have durable pain control. The radiation is directed at the trigeminal nerve as it exits the brain stem. The most common side effect from this treatment is numbness of the face and very rarely damage to the facial nerve. Dose delivered is between 70 to 80Gy calculated at the isocenter. The side effect described in the case of this patient could be related to the dose or site of treatment. Another risk factor is the presence of multiple sclerosis which could interfere with the treatment’s mechanism of action, although this does not apply to the patient in this case. I perform these procedures routinely with LINAC based machines for trigeminal neuralgia. It is very uncommon to see the complications that this patient has been left with. Further investigation as to how the procedure was performed, what equipment was used and what dosage was delivered is warranted. It is possible that the patient’s symptoms could be the result of a poorly conducted procedure or improper dosing.