An adherent nerve root – Classification and exercise therapy in a patient

An adherent nerve root – Classification and exercise therapy in a patient
diagnosed with lumbar disc prolapse
Martin Melbye*
Department of Physical Therapy, Aalborg Hospital/University Hospital of Aarhus, Hobrovej 18-22, DK-9100 Aalborg, Denmark
1. Introduction
In Denmark the McKenzie method is one approach frequently used by physical therapists treating back pain patients, including those with lumbar disc prolapse. Previous studies indicated that 83–88% of low back patients can be classified into one of the McKenzie syndromes and thereafter managed successfully with conservative care (May, 2004; Hefford, 2008).
The most common classification was Derangement syndrome (80%), whereas Dysfunction syndrome was found in only 3–6% of patients (May, 2004; Hefford, 2008). A subgroup of the Dysfunction category is adherent nerve root (ANR) (McKenzie and May, 2003). Thus, the ANR subgroup is a relatively rare finding in low back patients and therefore difficult to conduct randomized clinical trials on (Ellis and Hing, 2008). No previous case reports have described McKenzie assessment and management of patients classified as ANR.
The criteria for ANR classification are (McKenzie and May, 2003):
_ History of recent sciatica.
_ Symptoms present for at least 6–8 weeks.
_ Intermittent leg pain produced only when loading structurally impaired tissue.
_ Major limitation of flexion in standing.
_ Consistent movement produces pain that abates within minutes after the movement has stopped.
2. Patient presentation
2.1. History
The patient was a 31-year old male referred to an outpatient spine unit. The patient presented with intermittent sciatica (Fig. 1), maximum pain intensity 7 points on a 11-point numeric pain rating scale (Childs et al., 2005).
Previous treatment during this episode was physical therapy with massage and general exercises over an 8- week period without any effect on symptoms or functional abilities. As a result of the present problem, the patient had stopped bending his back more than absolutely necessary as hewas afraid to worsen his problem. His walking was impaired as he was limping and unable to take full strides with his left leg. He works as a software engineer and his work involves sitting at a computer desk and in meetings.
Two years ago he was rebuilding his house, which involved heavy lifting and stooped work positions. During these activities he gradually started to experience back pain that progressed with radiating symptoms into the left leg over some months. When he consulted for the first visit, his symptoms had not changed for 12 months. His leg pain is produced whenever he walks or bends over. Back pain is produced immediately when he sits down. Relieving factors are standing up straight or lying down.

He had less than five earlier episodes of low back pain over the last couple of years. These episodes had been of a few days duration and never before accompanied by sciatica.

2.2. Physical examination
Baseline neurological findings were decreased sensation on the lateral left foot, decreased left Achilles reflex and a positive left straight leg raise at 20 degrees elevation.
Range of motion assessment revealed a pain-related major loss of lumbar flexion, Lumbar extension and lateral flexion range of motion to each side was within normal range and did not produce symptoms. The patient had a slouched sitting posture and upon correction, into an erect posture, the back pain subsided immediately only to return once the patient was allowed to slouch again.
2.3. Provocative testing
In order to evaluate the patient’s tolerance to flexion loading, he was instructed in a programme consisting of 15 repetitions of lumbar flexion in supine lying, 5–6 times each day, if it produced concordant symptoms that did not subside within 5 min or he experienced obstruction of lumbar extension, as a mechanical sign of a symptomatic derangement.
2.4. Classification
On follow up 7 days later, he had been performing exercises as instructed. His symptoms and physical findings were unchanged. Data from the patient’s history and physical examination fit into the criteria for an ANR and a derangement was ruled out by failure to centralize as well as lack of response to provocative testing strategies.
3. Treatment second to third visit – Day 7 to week 4
The patient was instructed to continue with 6–8 repetitions of flexion exercises in lying followed by left leg neural stretches 6–8 repetitions, 5–6 times each day.
Also the patient was instructed to perform 10 repetitions of lumbar extension exercises in lying, to reduce the risk of recurrence (Larsen et al., 2002). For the same reason posture correction in sitting was enforced with the use of a lumbar roll.
On follow up at 4 weeks the patient had been exercising 3–4 times each day. Maximum pain intensity over the last 48 h had reduced from 7 to 3 on the 11-point numeric pain rating scale and the skin sensation on the lateral aspect of the left foot was normal. Straight Leg Raise now produced symptoms at 45 degrees of elevation.

4. Fourth to fifth visit – 6 weeks to 3 months
Exercises progressed to repeated flexion in sitting with the left knee straight, which produced concordant symptoms in the left leg. He was encouraged to perform 8 repetitions, 5–6 times daily. At visit number 5 the exercise was progressed to repeated flexion in standing 6–8 repetitions, performed 5–6 times per day and still the patient was instructed to also perform 10 repeated extension exercises in lying or standing.
5. Sixth visit – 5 months
At the final visit the patient reported freedom of symptoms for 4 weeks, he had not taken any analgesics for a month, walking was normal and pain free, sitting and bending over was pain free and the patient felt he had regained confidence in all functional activities including bending his spine. Improvement in lumbar flexion range of movement.
Neurological examination revealed sustained normal sensation at the lateral aspect of the left foot and left straight leg raise to 80 degrees with no symptoms but tightening in the hamstring. However, the left Achilles reflex was still decreased.
6. Discussion
This paper reported the McKenzie classification and management of a patient with an 18 month history of low back and sciatica, functional disabilities and fear related to bending. MRI showed a disc prolapse and the physical examination led to the conclusion that symptoms were caused by nerve root adhesions. Over 5 months, during which he performed regular end range lumbar flexion exercises, aiming to remodel the ANR, the patient regained normal range of motion, full functional ability, freedom of symptoms and confidence in bending his back.
ANR is a syndrome diagnosis and its validity has not been compared to any reference standard. Critics may suggest that this patient recovered in spite of, rather than as a result of, the pain provoking exercises. However, the clinical relevance of this case report is that patients with prolapsed discs and neurological deficits may not have to strictly avoid end range flexion loading even though it produces pain temporarily. Since the ANR classification is relatively seldom, randomized controlled trials of the exercise treatment are difficult to conduct and it is suggested that clinicians publish case studies or randomized controlled trial (N-of-1 trial) on this type of patient.
primephysio - HOME