A 71-year-old female with hypertension, dementia was transferred to our center from a community hospital for acute onset (2 days) of ascending weakness from feet up along with dizziness. No antecedent illnesses or fevers.

On exam, patient had a Medical Research Council (MRC) muscle strength of 2/5, 4/5 in bilateral lower extremities, bilateral upper extremities respectively with a normal sensory exam and loss of deep tendon reflexes. Due to the acuity of ascending paralysis, she was worked up for acute inflammatory demyelinating polyradiculoneuropathy (AIDP). Electromyography (EMG) / Nerve conduction study (NCS) showed features of prolonged latency, diminished nerve conduction velocities suggestive of primary demyelinating neuropathy. Lumbar puncture failed to demonstrate albumin-cytological dissociation.

Intravenous immunoglobulin (IVIG) was initiated for a total of 5 days with minimal improvement in symptoms.

Five days into admission, incidentally, a tick was noticed attached to the scalp while patient was being cleaned. The tick was identified as Dermacentor variabilis. Following tick removal, patient regained full strength with the return of deep tendon reflexes.

AIDP is the most common misdiagnoses associated with tick-borne paralysis as both have ascending paralysis. Progression of weakness over hours to days, absence of fever and having a normal sensory exam leans towards tick-borne paralysis. If recognized early, complete recovery is expected with tick removal and supportive care alone.