Medical emergency: rash, headache and spinal cord injury

Abstract

A 49-year-old consultant medical oncologist, with a medical history of complete T5 spinal cord injury (March 1992) and long-term paralysis from the chest down, presented with shingles affecting the T7 dermatome. He also had a dull frontal headache, a feeling of agitation and increased blood pressure of 135/90 on a home blood pressure machine (higher than his usual blood pressure of 90/70). Having been taught about autonomic dysreflexia at the time of his initial spinal cord injury, he self-diagnosed autonomic dysreflexia caused by the noxious stimulus of shingles below his level of spinal cord injury. He self-administered a nifedipine 5 mg sublingual capsule to decrease his blood pressure before urgently seeing his general practitioner. Treatment of the shingles with acyclovir and analgesia successfully managed the problem and avoided hospital admission. This case highlights key aspects in treating autonomic dysreflexia and the value of doctor–patient partnership in doing so.

Background

Autonomic dysreflexia is a life-threatening complication¹ that can occur in patients with neurological conditions which include spinal cord injury (at vertebral level of T6 and above),^2–4 multiple sclerosis^{5 6} and Guillain-Barre syndrome.⁷ It is caused by a noxious stimulus below the level of spinal cord injury,⁸ such as bladder distention, constipation/bowel impaction, pressure injuries, and skin and soft tissue infections including ingrown toenails. Autonomic dysreflexia has been reported in 48%–90% of people with chronic traumatic spinal cord injury (6 months or more after injury),^{9 10} and a bladder or bowel cause is the trigger in 95% of events.^{10 11}

Autonomic dysreflexia results in uncontrolled hypertension, clinically defined as an increase in systolic blood pressure of 25 mm Hg or more above the patient’s normal blood pressure.¹² The resolution of autonomic dysreflexia requires quick and decisive action. If untreated, it can result in intracerebral haemorrhage,¹³ retinal haemorrhage, cardiac arrhythmia,¹⁴ myocardial infarction, pulmonary oedema and death.¹⁵

This article outlines a case of autonomic dysreflexia, key aspects in its management, and the value of the general practitioner drawing on the patient’s knowledge of their condition to make a diagnosis and treatment plan in a timely manner.

Case presentation

A 49-year-old medical oncologist with a medical history of complete T5 spinal cord injury in March 1992 and long-term paralysis from the chest down noticed a painless rash which had gradually appeared over a period of 2 days (see figure 1). He did not usually get headaches and he had a dull frontal headache and a feeling of agitation. His blood pressure on a home blood pressure machine was 135/90, which was higher than his usual blood pressure of 90/70. Subsequently he self-administered a nifedipine 5 mg sublingual capsule at home to try to decrease his blood pressure and arranged to see his general practitioner urgently. The patient had no other symptoms of note.

Figure 1.

Unilateral rash in left T7 dermatome.

Investigations

The rash appeared 2 days before the patient presented to his general practitioner. Initially, there were only a couple of skin lesions. It was only in the morning that the patient arranged to see his general practitioner that it was apparent that the rash was in the left T7 dermatome (see figure 1) and a clinical diagnosis of shingles could be made. In this case, it was painless because it was below the vertebral level of the patient’s spinal cord injury.

Differential diagnosis

The differential diagnoses of the patient’s headache, agitation and high blood pressure include autonomic dysreflexia,¹ essential hypertension, migraine and cluster headaches, pheochromocytoma,¹⁶ malignant hypertension¹⁷ and posterior fossa neoplasms. These conditions can occasionally present with headaches and the signs and symptoms seen in autonomic dysreflexia.^{11 18}

Autonomic dysreflexia typically produces a sudden onset severe headache. It usually starts as a feeling of dullness which may progress to a severe throbbing bitemporal, occipital or frontal headache,⁸ although there is broad variation of pain features, and associated symptoms can vary from patient to patient. In this case, the headache was not as severe as a previous episode of autonomic dysreflexia, in which the patient had an unbearable pounding frontal headache due to bladder distention which was instantly relieved on urethral catheterisation.

Autonomic dysreflexia as a result of the noxious stimulus from shingles was the most likely diagnosis in this case because it provided a unifying diagnosis. The noxious stimulus of shingles was below the level of spinal cord injury, the pain from the shingles could not be felt by the patient and it was this that caused autonomic dysreflexia and associated hypertension. Normal resting blood pressure in patients with spinal cord injury is low¹⁹ and this patient’s usual blood pressure was 90/70. This meant that the blood pressure of 135/90 was significantly higher than normal for him. The diagnosis in this case benefited from the patient having knowledge of autonomic dysreflexia, and realising that the rash below the level of his spinal cord injury and associated headache suggested the possible diagnosis of autonomic dysreflexia.

Treatment

Aims of treatment are to find and treat the noxious stimulus causing autonomic dysreflexia and to treat the elevated blood pressure urgently with non-pharmacological and pharmacological interventions.²⁰ If untreated, autonomic dysreflexia can cause serious consequences such as haemorrhagic stroke, retinal haemorrhage, cardiac arrhythmia, myocardial infarction, pulmonary oedema and death.

Clinical guidelines on the management of autonomic dysreflexia²¹ recommend sitting the patient upright and loosening any constrictive clothing and assessing for common triggers of autonomic dysreflexia, namely bladder distention and bowel impaction. Pharmacological measures to decrease blood pressure include using short-duration antihypertensive agents, such as nitrates or nifedipine. Topical nitroglycerin has the advantage over sublingual nifedipine of being easily removed when the noxious cause is identified and treated and therefore has less of a risk of causing rebound hypotension. Other drugs that can be used are postsynaptic α−1 adrenoceptor blockers (prazosin), secondary amines (mecamylamine), anticholinergics (oxybutynin), β-adrenergic blockers and centrally acting α agonists (clonidine).

Sublingual nifedipine had already been administered by the patient to decrease the blood pressure²¹ and give more time to look for the cause of the autonomic dysreflexia. Also, the patient had got out of bed into his wheelchair to go to see his general practitioner which meant that he was now sitting. He had also ensured that he was in loose clothing and had no constrictive devices.

Of key importance was identifying and treating the cause of autonomic dysreflexia. The cause was the shingles, although the patient had also assessed himself for other causes of autonomic dysreflexia by doing intermittent urethral catheterisation to ensure he had no bladder distention, he had opened his bowels the previous evening and he had inspected his skin to ensure that there were no pressure injuries present. The shingles was treated with a course of acyclovir 200 mg five times per day for 5 days. He was also started on amitriptyline 25 mg once daily to treat the neuropathic pain associated with the shingles.²² In addition to this, he took regular co-codamol and ibuprofen for more immediate pain relief, while giving time for the amitriptyline to work.^23–26 He also had a supply of nifedipine 5 mg sublingual capsules to take when needed in case his blood pressure continued to increase despite these measures.

Outcome and follow-up

Clinical guidelines recommend that the patient is assessed for resolution of symptoms and that his blood pressure and heart rate are monitored for at least 2 hours to make sure that the episode has fully resolved.²¹ In this case, the patient continued to monitor his blood pressure and symptoms at home. He improved and his blood pressure decreased to its usual level on the first day. The shingles responded to the course of acyclovir and it took 2 weeks before the rash fully disappeared. At follow-up with general practitioner 4 weeks later, it was decided to continue amitriptyline 25 mg once daily because his long-term neuropathic pain due to nerve damage at the time of his initial spinal cord injury²⁷ had also been alleviated when on it. Had these measures not resolved the episode of autonomic dysreflexia, hospitalisation for monitoring and pharmacological control of blood pressure and further investigation for the potential cause of the episode of autonomic dysreflexia would have been necessary.

Discussion

Published articles indicate that autonomic dysreflexia results from a noxious stimulus below the level of spinal cord injury.^{8 28} The noxious stimulus below the level of the injury results in nerve impulses being sent to the spinal cord which are then blocked at the level of spinal cord injury causing reflex activation of the sympathetic nervous system and resultant constriction of blood vessels. This sympathetic surge causes anxiety/agitation and visual disturbance. The increase in blood pressure is detected by the heart and the carotid baroreceptors, which send signals to the brain. Then signals from the brain slow the heart via the parasympathetic vagus and dilate blood vessels via signals down the spinal cord.²⁹ However, these signals are blocked at the level of spinal cord injury and only blood vessels above the level of spinal cord injury are able to dilate. This results in symptoms of relative parasympathetic overdrive above the level of injury, which include flushing, piloerection, diaphoresis and nasal congestion. Unregulated acute onset hypertension occurs because there is continued vasoconstriction below the injury and the vasodilatation above the level of spinal cord injury is insufficient to overcome it. The classical haemodynamic derangement seen in autonomic dysreflexia is hypertension with relative bradycardia.

This case report is the only published case of shingles being the cause of autonomic dysreflexia. In this case, coming up with the diagnosis and treatment plan benefitted from the patient having been taught about autonomic dysreflexia when he had his hospital rehabilitation following his spinal cord injury. This enabled him to think about autonomic dysreflexia being the cause of the headache and also be aware of the serious potential consequences if left untreated. Also, having previously had a severe case of autonomic dysreflexia with an unbearable and more severe headache several years before due to bladder distention made the patient act quickly to try to avoid the situation getting that bad.

The patient was also aware that it would take longer to reverse the noxious stimulus of shingles when compared with bladder distention, which can easily be reversed by inserting a urethral catheter.

It should be noted that the majority of cases of autonomic dysreflexia are due to bladder distention or constipation/bowel impaction and these, in particular the former, can be quickly reversed without the need for pharmacological intervention. The case reported here of shingles causing autonomic dysreflexia was not quickly reversible, and non-pharmacological and pharmacological actions to decrease the blood pressure were necessary while treating the cause including providing analgesia for suspected pain from the shingles. The case highlights the importance of making the diagnosis of autonomic dysreflexia and of instituting the key aspects of treatment in a timely manner. It illustrates a good example of the general practitioner drawing on the patient’s knowledge in doing so. The vital importance of doctor–patient partnership in working together to come up with an effective and agreed management plan should not be understated.

Patient’s perspective.

I, the patient, am also the author of this case report. It took a while before I realised that I had shingles because initially I only had one or two spots. It was only after two days when I had more spots and they were clearly in the left T7 dermatome and my wife suggested shingles as a possible cause that I thought of shingles. Even though the headache I developed was only a dull frontal headache, I was aware that it is unusual for me to get headaches, and I was immediately concerned that I might be developing autonomic dysreflexia when I also felt a bit agitated. This made check my blood pressure on my home blood pressure machine straightaway and when I saw that it was elevated over my normal, I took a nifedipine capsule which I have to take for this eventuality. I knew that I needed urgently to treat the cause (the shingles) and the associated pain (which I couldn’t feel due to the shingles being below my level of spinal cord injury).

Since my spinal cord injury in 1992, I have experienced autonomic dysreflexia on several occasions. It can range in severity from a feeling of slight agitation and sweating above the level of my spinal cord injury, such as when needing to do an intermittent catheter when my bladder is nearly full (400 mL), to a pounding headache which is so bad that I think my head is about to explode. This latter experience has happened only once when my bladder was grossly overdistended (1000 mL), which was when I was first getting used to bladder management in the Spinal Injuries Unit having had my indwelling urethral catheter removed. Fortunately this episode of autonomic dysreflexia was easily rectified by having a urethral catheter reinserted giving instant relief.

In this most recent episode, I was worried because it would take longer for the noxious stimulus of shingles to respond to treatment (acyclovir). I was also aware that pain relief was important in resolving this episode of the autonomic dysreflexia. My general practitioner was excellent in listening to me as to what I thought the problem was and my concern about needing urgent treatment to try to avoid the autonomic dysreflexia getting worse. While autonomic dysreflexia was outside her field of expertise, she collaborated extremely well, was very supportive and was proactive in responding to my concerns by prescribing the necessary treatment and agreeing on a management plan. I had to continue to monitor my blood pressure and I would have to attend the hospital if my symptoms got worse and/or my blood pressure didn’t settle back to my usual level.

Learning points.

• Autonomic dysreflexia is a life-threatening emergency that can occur in patients with complete spinal cord injury above T6 vertebral level and other neurological conditions.

• It is caused by a noxious stimulus below the level of spinal cord injury, such as bladder distention, constipation/bowel impaction, skin and soft tissue infections including ingrown toenails.

• It presents with hypertension, bradycardia, nasal congestion, flushing, piloerection and diaphoresis above the level of the spinal cord injury.

• Key management measures are (1) treating the noxious stimulus and (2) decreasing the blood pressure by non-pharmacological measures (sit the patient upright and loosen any tight clothing) and pharmacological measures (administering topical nitrates or sublingual nifedipine) if the noxious stimulus cannot quickly be reversed.

• If untreated, it can result in haemorrhagic stroke, retinal haemorrhage, cardiac arrhythmia, myocardial infarction, pulmonary oedema and death.