A 37-year-old woman was involved in a frightening car accident, after which she was seen in the emergency room (ER) with many bruises, L2–L4 transverse process fractures, and multisite pain. Within 5 months, she developed a paralyzed distal right lower extremity and multiple emotional and cognitive symptoms. Numerous investigations and treatments (electrophysiological studies, lumbar magnetic resonance imaging (MRI) scans, specialist consultations, lumbar sympathetic blocks, neuropathic medications, and analgesics) failed to provide any pain relief or document structural damage. The patient was seen 3 years after the accident and admitted to our inpatient unit for further evaluation. On examination (O/E), she was wheelchair-bound, with severe allodynia and hyperalgesia in the right leg from the groin to the ankle, but completely anesthetic (with no voluntary movement) right foot. Similar but much milder findings were observed in the left leg. Deep tendon reflexes could not be elicited in the lower limbs. She received a single-blinded NS infusion followed by IV SP as per protocol. Baseline NRS pain ratings were 5–6/10 (right leg) and 3/10 (left leg). The patient failed to respond to the NS infusion. At 80 mg of SP, she complained of dizziness, allodynia/hyperalgesia was generally reduced in both legs, right leg pain was rated 4/10 (left leg pain was much less), but distal right foot anesthesia remained. At that time, she started crying “out of joy” as she “had never felt 4/10 right leg pain since her injury.” She was instructed to close her eyes and visualize the leg. While she was able to “see” the left leg/foot, the right leg “tapered and disappeared” at the ankle. We noted spontaneous movements of the left foot while she was visualizing herself playing the piano, but this was not observed in the right anesthetic foot, while repeated commands to actively move the right foot were fruitless. At the end of the SP infusion (200 mg), the patient complained of facial numbness, double vision, and drowsiness, with sensory abnormalities significantly reduced in the left leg but unchanged in the right. Leg pain was further reduced to 3/10 or less (right leg) and 1/10 (left leg). Subsequently, the patient fell asleep.

The team (after psychological investigations, review of all consultations, and results of the SP interview) concluded that the patient had a functional neurological disorder (established shortly after her frightening car accident, which generated both physical and psycho-emotional injuries). We also considered that her sensory and motor changes were of central origin (“maladaptive neuroplasticity”), and in our opinion “permanent” in the right leg, while those in the left leg had a chance of improvement. Indeed, the patient, who was followed up for 5 years afterwards, never regained sensation or power in the right foot despite numerous treatments including neurofeedback, mirror therapy, visualization, and cognitive behavioral therapy, while she regained some power and sensation in the left foot. She continued to remain severely disabled with bilateral elbow crutches at home and wheelchair outside the house.

Take-home message: The patient’s clinical presentation with inability to “visualize” her anesthetic foot (similar to patients who have amputations) in combination with paralysis and persistence of anesthesia under SP, led the team to the conclusion that her right leg sensory abnormalities were permanent in nature. This indeed proved to be so over the many years of follow-up.

A 56-year-old man developed gradual weakness, shooting pain, and loss of sensation in the left leg, which rendered him wheelchair-bound. One year later, he was diagnosed with thoracic myelopathy due to ligamentum flavum hypertrophy and underwent T9–10 laminectomy and decompression, which resulted in marked improvement in weakness and 80% pain relief. During convalescence, he developed necrotizing granuloma in the left leg that required surgery and drainage over a period of a few months. During this time, he regressed severely (both physically and emotionally) and ambulated with a wheeled walker. He was seen by our team 4 years after thoracic surgery and was admitted to our inpatient unit. Detailed psychological assessment disclosed lasting emotional trauma from loss of his government job. O/E, he had a slightly colder left foot, deep tendon reflexes were 2+ in both the upper and lower extremities, and tone, bulk, and strength were preserved. Sensory examination of the left leg, however, demonstrated a sharply demarcated and rather dense reduction of sensation to light touch, pinprick, and cold perception from the groin to the foot. His baseline back and left leg pains were 8/10. After 10 ml of NS, there was no change in sensory abnormalities or pain ratings. At 3 cc (120 mg) of SP, he experienced some drowsiness, and the sensory abnormality completely normalized, so that the sensation in the left foot to touch and pinprick was fully restored and his pain became imperceptible. The infusion was terminated at that level and the patient was left to sleep.

Given his previous thoracic surgery, the characteristics of his pain, and his response to SP, the team felt that his sensory deficit (an indication of neuroplasticity) was not permanent. After healthy life changes (diet, engagement in aqua fitness) and mindful meditation, all of which greatly improved his emotional state, we felt that the patient had become an appropriate candidate for a trial of spinal stimulation (though his sensory deficit was unchanged). Insertion of the St. Jude Medical Prodigy neurostimulation device was performed 1.5 years after SP infusion. This particular stimulator delivers closely spaced high-frequency stimulation, known as “burst” stimulation, to the spinal cord, and does not generate paresthesia in the affected limb, in contrast to classic tonic neurostimulation devices. Spinal stimulation resulted in a substantial decrease in pain and instantaneous elimination of the foot hypesthesia upon turning on the stimulator. However, when the stimulator was turned off, the sensation would immediately decrease, and the pain would increase to unbearable levels, with bursts of shooting pain from the back to the foot. To the date of this paper many years later, the stimulator effects remain unchanged.

Take-home message: Based on the SP interview, we considered that the sensory deficit was the result of central maladaptive changes which were reversible. This was indeed proven over the years of stimulator use.

A 21-year-old female behavioral social worker was injured at work after one of her patients attacked her and dropped her on her left knee, resulting in knee swelling and pain. One month later, while working with crutches on modified duties, she stumbled on wet floor and fell. This was a Workers Compensation claim and the patient felt maltreated at work.

A month after her second injury, she was seen in consultation. Her pain was rated 7/10, ranging from 6/10 to 8/10. O/E, she walked with crutches while maintaining the knee in fixed 35° flexion and was barely able to move ankles or toes. The left leg was colder, with reddish discoloration in the distal foot and slight swelling in the left knee (but not foot). Sensation to light touch, pinprick, manual pressure, vibration, and cold were reduced from the left groin to the mid-shin, after which the distal leg and foot were completely anesthetic to all testing modalities.

The patient was admitted to our hospital’s rehabilitation beds with a provisional diagnosis of functional neurological symptom disorder (FND) according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM 5) and complex regional pain syndrome. She was administered a single-blinded intravenous infusion of NS followed by SP and failed to respond to 10 ml NS. However, after 200 mg of SP, the patient reported 7/10 pain, remained conscious, and the knee was passively partially extended. After 400 mg SP, her pain remained 7/10 but her sensory deficit partially normalized, and while she was awake (see Fig. 2), although somewhat sedated, we were able to fully extend the left knee passively.

Photo 1: case report 3. Near-full (left) knee extension after administration of 400 mg SP. The patient was awake, though mildly sedated

One day later, she had returned back to her baseline. The test was repeated, but this time with a single slow infusion of 400 mg SP/1t NS over 2 h, a procedure we often performed on subsequent days with the psychologist conducting a detailed evaluation. At 200 mg, she was alert and able to extend her left knee fully, knee pain decreased to 1/10, and was able to stand up and go to the washroom unaided with straight knee full weight-bearing and landing on the left foot; however, her hip pain and sensory deficit did not improve. The next day, she rated her pain as 7/10 across the entire left leg, and while she displayed an anesthetic distal leg, her hypesthesia at the thigh and above the knee had fully resolved. Upon discharge, her knee was kept again in flexion as much as before, despite the fact she was shown photos of straight knee obtained during the SP infusion.

She refused our offer for a charge-free comprehensive pain management program (including active rehab, psychological counseling, mindfulness, nutritional counseling, etc.), while Workers Compensation had approved funding for transportation for the duration of the program.

Take-home message: Based on the SP interviews, clinical assessment, psychological assessment, and the patient’s refusal to undergo interdisciplinary pain management, the team concluded that the patient combined elements of FND (given changes in range but also sustained reduction in sensory deficit) AND conscious “simulation of disease process” as, despite her full knowledge of intact range of motion having seen photos, she denied our treatment offer and elected to pursue the role of disabled on compensation benefits.