Detecting The Differences Radiculopathy, Myelopathy And Peripheral Neuropathy

In the name of Allah the Beneficent the Merciful

Detecting the Differences Radiculopathy, Myelopathy and Dr Zafar Iqbal Department of Neurosurgery Abbasi Shaheed Hospital Karachi

Points to note …..  Radiculopathy,

myelopathy, and peripheral neuropathy have common overlapping symptoms, but each has a unique physiological mechanism underlying the sensory and motor disturbances associated with each disorder.

Points to note …..  While

the physical exam should reveal characteristics that differentiate one pathology from another, in order to prevent an incorrect diagnosis, the list of differential diagnoses should be examined before treatment is started.

Points to note …..  Further

work-up may be necessitated by other disease processes that present with common symptoms, if the patient does not respond to well regarded treatment or new symptoms develop during treatment.

Radiculopathy  Radiculopathy

occurs as a result of biomechanical pressure on a nerve root with subsequent biochemical release of inflammatory mediators

(Starkweather, Witek-Janusek & Mathews, 2005).

Radiculopathy Biomechanical pressure at the point of the dorsal root ganglion (nerve root that directly dissects from the spinal cord) or peripheral nerve can be caused by  disc tissue,  tumors, or  bone.

Radiculopathy often has a quick onset and is characterized by a shooting pain that radiates down the extremity.  Patients often present with symptoms present upon awakening in the morning, without identifiable trauma or stress. 

Radiculopathy Clinical findings include  pain,  dermatomal sensory disturbances,  weakness, and  hypoactive muscle stretch reflexes in the distribution of the affected nerve root

Radiculopathy cervical herniated disc is the most common reason for upper extremity radiculopathy

Radiculopathy

Radiculopathy Motor and sensory loss will be specific to the nerve root involved

Radiculopathy

Almost all herniated cervical discs cause painful limitation of neck motion, with aggravation of pain during neck extension.

Radiculopathy  Left

C–6 radiculopathy occasionally presents with chest or scapular pain  C–8 and T–1 nerve root involvement may cause a partial Horner’s syndrome due to interruption distal to the superior cervical ganglion.

 Over

90% of patient with acute cervical radiculopathy due to cervical disc herniation will improve without surgery (Saal, Saal, &Yurth, 1996).

 The

recovery period can be treated with adequate pain medication, mainly nonsteroidal anti-inflammatory types and muscle relaxants. Short course tapered steroids and intermittent cervical traction (10–15 pounds for 10–15 minutes 2–3 times daily) may also be used.

 In

patients that have progressive neurological deficits (i.e. weakness) of the affected muscle groups, however, surgery may provide the best long-term outcomes

cervical discectomy  Anterior

cervical discectomy with fusion (ACDF) or without fusion (ACD) or posterior cervical foraminotomy may be used for resection of a cervical disc herniation

selection of the surgical procedure  reasonably

be based on the preference of the surgeon and tailored to the individual patient.

cervical disc replacement  may

likely be available to the general public in the near future. Clinical trials on the efficacy of disc replacement surgery have continued with promising outcomes (Phillips & Garfan, 2005).

Cervical disc replacement  preserves

motion at the instrumented level/s and can potentially improve load transfer to the adjacent levels compared with fusion. There are several different models that are presently seeking FDA approval

Risks associated with surgery  neurological

dural tear,  infectionthe 

injury,

Risks  long-term

voice disturbances  dysphasia.  incidence of new-onset dysphasia after surgery is 29.8% at three months,  6.9% at six months, and  6.6% at two years.

Risks  The

use of plates resulted in a 1.6-times higher incidence and higher rates were noted following multi-level procedures and at more cephalic levels.  a smaller and smoother plate profile reduced the incidence and severity of post-operative dysphasia.

plating affects the adjacent levels  Most plate designs use oblong holes, and, as settling occurs, the plate translates toward the next adjacent non-fused level (Cervical Spine Research Society, 2005). Plates within 5 mm of non-fused disc spaces have been associated with adjacent-level disc ossification. 

Risks  This

phenomenon, when occurring within three months after surgery, is likely to be progressive. However, Rao and colleagues (2005) suggest that fusion does not generally affect adjacent levels in the cervical spine.

Myelopathy Functional disturbance or pathological change in the spinal cord is referred to as myelopathy

Myelopathy It is often caused by pressure around the spinal cord. This syndrome usually has a prolonged onset, occurring over months to years

Differential Diagnosis

Patients may present with  an

inability to button their clothes,  turn doorknobs and  may complain of dropping objects often.

CSM  Cervical

spondylosis is the most common cause of myelopathy in patients over 55 years of age (Greenberg, 2006). Spondylosis, a term used to describe widespread degenerative condition of the discs and vertebrae, can cause direct cord compression.

Cervical spondylotic myelopathy  develops

in almost all patients with over 30% narrowing of the cross-sectional area of the cervical spinal canal, although some patients with severe cord compression do not develop myelopathy.

CSM Osteophytes and hypertrophy or enfolding of the ligamentum flavum may also contribute to spinal cord compression

These processes narrow the canal causing ischemia of the cord and degeneration of the central grey matter at the level of compression

Damage  to

the posterior columns above the lesion and demyelination in the lateral columns, especially the corticospinal tracts, below the lesion, causes  changes in sensory and motor function. Thus, a mixture of  upper motor and  lower motor neuron findings in cervical myelopathy may be found.

Clinical Features There may be  weakness and  wasting of hand muscles  with slow, stiff opening and closing of the fists, resembling arthritis.

Clinical Features  Clumsiness

with fine motor skills  proximal weakness of the lower extremities, notably iliopsoas weakness occurs in 54%, and  spasticity of the lower extremities with most having hyperactive reflexes (clonus and Babinski’s sign). .

Clinical Features  Glove

distribution sensory loss in the hands may be present and most have loss of vibratory sense in the lower extremities

Amyotrophic lateral sclerosis (ALS)  is

commonly misdiagnosed as cervical spondylosis.

Common findings of ALS       

include: atrophic weakness of the hands and forearms mild lower extremity spasticity and diffuse hyperreflexia, but sensory changes are absent. Dysarthria or hyperactive jaw-jerk may be the first clue. Hyperactive jaw jerk indicates upper motor neuron lesion above the midpons and distinguishes long tract findings above the foramen magnum from those below. Fasciculation of the tongue or in the lower extremities may also occur in ALS.

Electromyelography (EMG)  Electromyelography

(EMG) is the diagnostic test used to confirm ALS.

MRI  Careful

consideration of chiari malformation, syringomyelia, hydrocephalus and cervical spondylosis with cord compression were used when evaluating the films.

Surgery  cervical

laminoplasty, a procedure to decompress the spinal canal by removing a part of the lamina of the affecting vertebrae.  Anterior cervical discectomy or vertebrectomy  with or without fusion may be used to treat anterior disease up to three levels.  The posterior approach,  Decompressive cervical laminectomy  with or without fusion may be used if the disease is primarily posterior or if surgery is required in more than three levels.

cervical laminoplasty  was

associated with better clinical outcomes (functioning, pain) and less complications than decompression and fusion.

Indications for surgery  are

primarily patients with radiological evidence of spondylotic degeneration of the cervical spine with progressive symptoms, and/or pain.

Severity and Progression  Thus,

the importance of determining severity and progression of symptoms is vital as the goal of surgery is to stop the progression, while recovery of symptoms is variable.

Laminoplasty  has

gained in popularity for the treatment of cervical myelopathy secondary to  ossification of the posterior longitudinal ligament and  spondylosis with spinal stenosis

Peripheral neuropathy  Peripheral

neuropathy occurs as nerve roots, which extend to the distal portion of each extremity, are damaged.

Etiology  The

exact cause is unknown but is thought to be mediated by inflammation, ischemia and demyelination of the larger peripheral nerves

Etiology  Diabetes,  alcohol

and  Guillain-Barre accounting for 90% of cases

Evaluation for the initial workup for peripheral neuropathies of unknown etiology should include  Hgb-A1C,  TSH,  ESR,  vitamin B12 and  EMG studies.

Over 50% of patients with diabetes mellitus (type I and type II)  develop

neuropathic symptoms (Perkins, 2002). Diabetic neuropathy may be slowed with tight glucose control, while in patients with impaired glucose tolerance; diet and exercise have been shown to significantly improve neuropathic pain (Laino, 2004)..

 Even

in patients that have diabetes, evaluation of other causes for neuropathy is advocated. Gorson and Ropper (2006) found that 53% of 103 diabetic patients with polyneuropathy had additional causes, such as  vitamin B deficiencies,  renal disease,  alcohol overuse, and  neurotoxin medications

Drugs        1. 2. 3.  

Thalidomide Metronidazole (Flagyl) Phenytoin (Dilantin), Amitriptyline (Elavil), Dapsone Nitrofurantoin (Macrodantin) Cholesterol Lowering Drugs Such As Lovastatin (Mevacor) Indapamide (Lozol) Gemfibrozil (Lopid) Thallium, And Chemotherapy (Cisplatin, Vincristine)

Guillain-Barre syndrome  presents

as an acute onset of peripheral neuropathy with progressive and symmetric muscle weakness (more severe proximally) with areflexia.

Guillain-Barre syndrome This occurs with focal segmental demyelination with endoneurial monocytic infiltration; the exact cause of the disease, however, remains unknown. Patients are diagnosed based on presentation and progression of symptoms, nerve conduction studies and through cerebral spinal fluid analysis

Perioperative neuropathies Most sensory neuropathies that develop perioperatively or after cardiac catheterization resolve over time, but motor neuropathies can be transient or permanent

Gabapentin a neuroleptic drug, has been advocated for treatment of neuropathic pain including peripheral nerve injury (National Guideline Clearinghouse, 2003).

Nerve Growth Factor  Recombinant

human Nerve Growth Factor (rhNGF) may be the first treatment that actually repairs nerves  rhNGF is a manufactured form of a naturally produced chemical that signals the body to produce, repair and strengthen small nerves

Conclusion  Patients

presenting with radiculopathy, myelopathy or peripheral neuropathy may have several overlapping symptoms. The physical exam should provide the practitioner with a differential diagnoses scheme that will allow correct diagnosis and treatment

………  In

general, the absence of weakness should allow the practitioner time for an adequate work-up of the most common diagnoses through laboratory or radiological tests. It is imperative that the practitioner continues to evaluate treatment regimens for their effectiveness and revisit the differential diagnoses so that the patient does not continue down the wrong treatment path. In addition, helping patients to recognize healthy life style habits that may affect their symptoms is crucial