Osteoarthrosis causing altered mental status: a case report

Abstract

IntroductionCervical spondylosis as a cause of diaphragmatic weakness is an uncommon entity and has been reported primarily in the setting of cervical spinal cord compression. Cervical spondylosis most often causes respiratory failure from cervical myelopathy and damage to the ventral horn cells at spinal cord segments C3 to C5 from where the phrenic nerve arises. The manifestations are variable but there may be evidence of upper motor neuron signs and neurological deficits in the lower extremities along with Lhermitte’s sign. Here we report a rare case of cervical spondylosis causing phrenic nerve root compression from foraminal narrowing at C3, C4 and C5, leading to lower motor neuron paralysis of the phrenic nerve and respiratory failure, in the absence of spinal cord involvement.Case presentationAn 87-year-old Caucasian man presented with recurrent episodes of hypercapnic respiratory failure and altered mental status requiring intubation. He was noted to have neurological deficits in his upper extremities with C5 radiculopathy deficits. An arterial blood gas showed a normal alveolar-arterial oxygen gradient with chronic respiratory acidosis, and pulmonary function testing showed restrictive lung mechanics with weakened neuromuscular apparatus and low maximum inspiratory and expiratory pressures. An extensive workup including electromyogram and magnetic resonance imaging showed evidence of phrenic neuropathy secondary to C3 to C5 neural foramina compression, from cervical spondylosis. He was treated conservatively with night-time bilevel positive airway pressure which rested his respiratory musculature with significant improvement.ConclusionsCervical spondylosis leading to phrenic nerve root compression is a rare and underreported cause of chronic respiratory acidosis and must be considered in the differential diagnosis of chronic hypoventilation, particularly in the elderly. This case illustrates how a simple arterial blood gas and calculation of the alveolar-arterial oxygen gradient can help in the workup of chronic respiratory acidosis by identifying causes of hypoventilation, which are associated with a normal diffusing lung capacity and thereby a normal alveolar-arterial oxygen gradient.

Dyspnea Associated with Cervical Spondylotic Radiculopathy: A Case Report and Review of Literatures

“…Dyspnea is an extremely rare symptom in cervical spondylosis, making it difficult to diagnose alone. To our best knowledge, only 10 cases of phrenic nerve palsy associated with cervical spondylotic radiculopathy exist, including the present case [2][3][4][5][6][7][8][9][10] (Table 1), with nearly the same number of case reports associated with cervical myelopathy, [11][12][13][14][15][16][17][18][19] and some case series showed a declined respiratory function in cervical myelopathy. 20,21) Diagnosis of dyspnea associated with cervical spondylotic myelopathy is relatively straightforward because canal stenosis is easy to be recognized on radiological…”

Cervical foraminal stenosis causing unilateral diaphragmatic paralysis without neurologic manifestation

“…[ 8 ] Moreover, EMG/NCS might provide evidence of degenerative neuromuscular diseases, such as amyotrophic lateral sclerosis or myopathy. [ 5 ] Unfortunately, neither EMG nor NCS were performed in our case.…”

“…Recent studies reported that electromyogram (EMG) and nerve conduction studies (NCS) might be helpful to diagnose hemidiaphragmatic paralysis. [ 5 , 8 ] Transcutaneous phrenic nerve stimulation in NCS shows a decrease in amplitude compared with the other side and EMG reveals radiculopathy, suggestive of nerve root compression. [ 8 ] Moreover, EMG/NCS might provide evidence of degenerative neuromuscular diseases, such as amyotrophic lateral sclerosis or myopathy.…”

“…Surgery for decompression should be recommended for patients with hemidiaphragmatic paralysis resulting from cervical spondylosis. Reddy et al [ 5 ] reported that an 87-year-old male patient with diaphragmatic weakness from cervical spondylosis refused to undergo surgery and transitioned to hospice care 2 years later due to right ventricular failure and pulmonary hypertension, despite conservative care that included biphasic intermittent positive airway pressure and diuretics.…”

An unusual case of orthopnea

“…To the authors' knowledge, there are only eight previously reported cases of phrenic nerve palsy secondary to cervical spondylosis, thus demonstrating the unusual nature of our case. [3][4][5] Seven cases report phrenic nerve palsy with myelopathy and one in the context of C5 radiculopathy. Our patient had no other discernible cause of diaphragmatic paralysis and the rationale for cervical spondylosis is compelling given the patient's cervical pathology at C3-C5, the origin of the phrenic nerve.…”