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Recovery from hemidiaphragmatic paralysis with improved respiratory function following cervical laminoplasty and foraminotomy: illustrative case

BACKGROUND Hemidiaphragmatic paralysis can occasionally be caused by cervical canal and foraminal stenosis. Rarely is the effect of surgical decompression on hemidiaphragmatic paralyzed patient respiratory function recorded. This report details a case of postoperative respiratory function restoration in a patient with cervical spondylosis–related hemidiaphragmatic paralysis. OBSERVATIONS A 77-year-old woman suffered hemidiaphragmatic paralysis caused by cervical canal and foraminal stenosis. The phrenic nerve palsy was thought to be caused by compression of the cervical spinal cord and its nerve root. The patient received a C3 laminectomy, a C4–6 laminoplasty, and a left C3–4 and C4–5 posterior foraminotomy. After surgery, she improved her maximum inspiratory pressure and respiratory function. LESSONS Cervical canal and foraminal stenosis may cause hemidiaphragmatic paralysis due to radiculopathy-induced phrenic nerve palsy. Laminoplasty and posterior foraminotomy can restore respiratory dysfunction related to diaphragmatic paralysis by decompressing the ventral horn of the spinal cord and spinal nerve root.

Hemidiaphragmatic paralysis may occur from direct trauma and phrenic nerve damage due to an adjacent tumor, neuropathy, inflammation, or iatrogenic procedure. 1 Cervical spondylosis is a rare cause of phrenic nerve palsy and hemidiaphragmatic paralysis. 2 We encountered a woman with cervical spondylosis with foraminal stenosis who experienced symptomatic hemidiaphragmatic paralysis. The patient received cervical laminoplasty and foraminotomy using an exoscope.

Illustrative Case History
A 77-year-old woman experienced numbness in both arms and hands with hand clumsiness for a few years. Two months before her presentation to our hospital, the patient had difficulty raising her left arm. In addition, she developed dyspnea on exertion. Her medical history included hypertension and diabetes mellitus. She had undergone carpal tunnel release for right carpal tunnel syndrome 15 years earlier. Additionally, the patient had undergone a right C6-7 uncovertebrectomy for right cervical radiculopathy 10 years earlier. She had a history of smoking 20 cigarettes per day until 17 years earlier.

Examination
The patient had left arm weakness. Her Medical Research Council grades were 3/5, 4/5, and 4/5 for the left deltoid, left biceps, and left triceps, respectively. The bilateral biceps and brachioradialis reflexes and right triceps reflex were diminished. Dysesthesia was observed in the bilateral C5-7 dermatome. The gait was spastic.

Postoperative Course
After the operation, symptoms of hand clumsiness, spastic gait disturbance, and dyspnea improved. Postoperative cervical CT (

Discussion
Observations Cervical spondylosis is a rare cause of hemidiaphragmatic paralysis. [2][3][4] A literature search identified seven cases of hemidiaphragmatic paralysis related to cervical spondylosis [5][6][7][8][9][10][11] (Table 1). These patients had dyspnea with motor and sensory symptoms from cervical myelopathy and radiculopathy. [5][6][7][9][10][11] A case that solely exhibits dyspnea and  no other accompanying spinal symptoms may create a diagnostic challenge. 8 In these cases, as well as the present case, phrenic nerve palsy is considered to cause hemidiaphramgatic paralysis. The phrenic nerve originates mostly from the C4 nerve root but also occasionally from the C3 and C5 nerve root; hence, spinal nerve root compression at the C4 level, and maybe at the C3 and C5 levels, is the cause of phrenic nerve palsy. 12 Phrenic nerve palsy may also result from compression of the spinal cord's ventral horn cells. [9][10][11] It is challenging to pinpoint the precise location of the stenotic lesion that is causing the phrenic nerve palsy. In most of these instances, the cervical canal and numerous levels of the cervical foramina developed spondylotic stenosis. As a result, some patients had multilevel foraminotomies [5][6][7][8] and cervical laminoplasty with foraminotomy. 7,9,10 It is advised to decompress both the spinal nerve roots consisting of the phrenic nerve and the ventral horn cells of the spinal cord to cover the potential pathogenetic regions. The posterior foraminotomy frequently necessitates the angled surgical trajectory. A 4K 3D exoscope, 13 like other surgical illumination modalities, is suitable for such observation in a constrained surgical field. 14 In our patient, hemidiaphragmatic paralysis resolved postoperatively within a week, and respiratory muscle strength improved concurrently. Repeated chest radiography 15 and spirometry 2 demonstrated recovery from hemidiaphragmatic paralysis and improved respiratory function following surgery. Repeated MIP and MEP readings on the spirometry indicated that the respiratory muscle strength had recovered. The MEP measures that for the chest and abdominal wall whereas MIP measures a mobility index for the diaphragm (Fig. 2C). Therefore, the overall respiratory function may benefit from hemidiaphragmatic paralysis recovery.
In the reported cases, it took between 2 weeks and 10 months after surgery to recover respiratory function. [5][6][7][8][9][10][11] A continuing recovery and rehabilitation program may be required because some patients need more time to regain their respiratory function.

Lessons
Although a single case report limits the significance of the observations, the lesson is that cervical canal and foraminal stenosis may cause hemidiaphragmatic paralysis due to radiculopathy-induced phrenic nerve palsy. Laminoplasty and posterior foraminotomy can restore respiratory dysfunction related to diaphragmatic paralysis by decompressing the ventral horn of the spinal cord and spinal nerve root.