A Man With Acute Areflexic Paralysis and Central Nervous System Symptoms

A 43-year-old man presented initially to an ophthalmologist complaining of double vision for 3 weeks. Ten days later, he developed numbness and weakness in both upper extremities which then progressed to his right lower extremity; 5 days afterward he presented to the emergency room because his symptoms had worsened. He denied bowel or bladder dysfunction, headache, neck pain or trauma, diarrhea, or respiratory infection.

Past medical history was significant for a 2-year history of intermittent hand tingling which had been diagnosed as carpal tunnel syndrome, but the surgical release of the median nerve failed to provide relief. One year prior to the presentation, he had bilateral foot tingling which lasted 1 week. For the past 2 years, he had intermittent shocklike sensations going down his back upon flexing the neck. He had medication-controlled hypertension and mild diabetes mellitus controlled by diet.

Social history revealed 2-pack-a-day cigarette smoking, but he denied alcohol abuse. He is a woodworker and denied any exposure to toxins.

Family history was significant for Guillain–Barré syndrome (GBS) in his father and breast cancer in his mother.

Neurologic examination showed normal mental function, pupils, and visual fields. There was mild diplopia on right lateral gaze and mild peripheral bilateral facial weakness. Strength was 4/5 in the upper extremities and 3/5 in both lower extremities. Reflexes were 1+ in the upper extremities, trace at the knees, and absent at the ankles; plantar reflexes were mute. Sensory examination revealed mildly decreased pinprick and vibration senses to the ankles. Coordination was preserved. He was unable to walk. The rest of the examination was normal.

What is the Differential Diagnosis?

This patient presented with an acute diffuse paralytic illness that progressed in 4 days. He had diminished reflexes and mild sensory abnormalities that were out of proportion to the weakness. The lack of a cord sensory level or sphincter disturbance argued against a myelopathy. The diminished reflexes and sensory findings suggested an acute neuropathy, and for this reason the differential diagnosis in cases like this should include arsenic poisoning and porphyria, suggested by his father’s similar illness. There was no other history or clinical findings to suggest either disease, and the cranial nerve abnormalities argued against both arsenic poisoning and porphyria. The most likely diagnosis would be an acute inflammatory demyelinating polyradiculoneuropathy (AIDP) or GBS. Tests for Lyme and HIV should also be done. The absence of fever was against a diagnosis of diphtheria. West Nile virus and COVID-19 had yet to be seen in the United States at the time of his presentation; also, weakness in that disease is usually asymmetric.

Extraocular weakness occurs in GBS and its variants but can also suggest a primary central nervous system condition such as multiple sclerosis (MS). The history of a Lhermitte’s sign and the episodic sensory and motor symptoms are also suggestive of MS. The sign, however, occurs not only in MS but also in patients with cervical spondylosis, spinal cord lesions, and demyelinating disease of peripheral nerves. The lack of long tract signs or urologic symptoms lowered the probability of MS.

An EMG Test was Performed

Motor Nerve Studies

Nerve and Site	Latency (ms)	Amplitude (mV)	Conduction Velocity (m/s)
Peroneal Nerve R.	Normal ≤ 5.7	Normal ≥ 3	Normal ≥ 40
Ankle	8.9	0.8	–
Fibular head	21.2	0.5	29
Knee	22.7	0.4	56

Tibial Nerve L.	Normal ≤ 5.3	Normal ≥ 4	Normal ≥ 40
Ankle	9.1	1	–
Pop. fossa	27.4	0.3	26

Median Nerve R.	Normal ≤ 4.2	Normal ≥ 6	Normal ≥ 50
Wrist	7.5	4	–
Elbow	13.2	3	48

Ulnar Nerve R.	Normal ≤ 3.6	Normal ≥ 8	Normal ≥ 50
Wrist	5.4	3	–
Below elbow	10.5	1	47
Above elbow	16.1	1	21

Nerve and Site	Latency (ms)	Amplitude (mV)	Conduction Velocity (m/s)
Facial Nerve R.
Side-to-side comparison	6.2	2	–

F-Wave and Tibial H-Reflex Studies

NR, No response.

Nerve	Latency (ms)	Normal Latency ≤ (ms)
Peroneal nerve R.	NR	54
Tibial nerve L.	NR	54
Median nerve R.	43.1	30
Ulnar nerve R.	39.1	30
H-reflex R.	NR	34
H-reflex L.	NR	34

Sensory Nerve Studies

Nerve	Latency (ms)	Normal Latency ≤ (ms)	Amp (μV)	Normal Amp ≥ (μV)
Sural nerve R.	NR	4.0	NR	11
Median nerve R.	NR	3.1	NR	20
Ulnar nerve R.	NR	3.1	NR	13

EMG Data

Muscle	Insrt Activity	Fibs	Pos Waves	Fasc	Amp	Dur	Poly	Pattern
Biceps brachii R.	Norm	None	None	None	Norm	Norm	None	Full
Flexor carpi ulnaris R.	Norm	None	None	None	Norm	Norm	None	Full
First dorsal interosseus R.	Norm	None	None	None	Norm	Norm	None	Red
Vastus lateralis R.	Norm	None	None	None	Norm	Norm	None	Red
Tibialis anterior R.	Norm	None	None	None	Norm	Norm	Few	Red
Gastrocnemius R.	Norm	None	None	None	Norm	Norm	None	Red