Acute Presentations in Chronic Neurologic Conditions

Acute Presentations in Chronic Neurologic Conditions

Jeremy Rose


Neurologic conditions are typically diagnosed and managed in the outpatient setting. Many of the diagnostic tests that are staples of neurologic practice are difficult to access or simply not accessible in the emergency department (ED). Although magnetic resonance imaging (MRI) is becoming more available, it is time-consuming, often not appropriate in stable chronic complaints, and unsuitable for an unstable patient. Electroencephalogram (EEG), neuromuscular testing, and much of the autoimmune-focused blood work are generally not available in a timely fashion. Nevertheless, patients with neurologic conditions frequently present to the ED with an exacerbation or progression of their disease; thus, the emergency clinician must be familiar with stabilization strategies. Even if the diagnosis is beyond the purview of the emergency clinician, discovering and documenting neurologic deficits can greatly assist clinicians in the future in establishing symptom chronicity and correlating progress with diagnostic testing and treatments.


Multiple Sclerosis (MS)

MS is the most common inflammatory neurologic condition seen in the ED. The current prevalence of MS in the United States is 149 per 100,000 individuals and is 3 times more common in women. Optic neuritis is, by far, the most common initial presentation, occurring in roughly half of patients with MS. That said, optic neuritis can occur in isolation and only half of the patients with optic neuritis will develop MS within 15 years of initial presentation.1 Painful vision loss, though, tends to be a motivation to seek an emergent evaluation; thus, optic neuritis often brings patients to the ED rather than to an outpatient clinic. MS can also present as isolated motor deficits or vague sensory disturbances; its relapsing-remitting nature can make it hard to diagnose on an initial evaluation.

Advanced MS and its complications frequently present to the ED with problems that are not specifically neurologic. Depending on the degree of involvement and areas of the brain affected, MS-related symptoms can include sensory disturbances, bowel/bladder dysfunction, visual
symptoms, muscle spasticity, and pain. Urinary dysfunction and paroxysmal motor weakness tend to present earlier in the disease course, whereas cognitive impairment and sensory alterations tend to be features of advanced disease. Some patients with advanced illness may become partially insensate, placing them at risk for injuries and prone to pressure ulcers.

The criteria for diagnosing MS rely on clinical deficits separated by space and time; however, characteristic white matter lesions on MRI can be highly suggestive of the disease. Although the cause of MS is unknown, it is characterized by inflammatory central nervous system (CNS) lesions that cause nerve demyelination and cell death. This inflammation appears to be the end result of an autoimmune cascade with genetic and environmental triggers.2 Accordingly, treatment is aimed at reducing this inflammation.

The usual treatment for optic neuritis, regardless of the presence of MS, is intravenous (IV) methylprednisolone 1000 mg/day for 3 days followed by 11 days of oral prednisone.3 Several randomized controlled trials (RCTs) have compared IV methylprednisolone to high-dose PO prednisone and found that symptoms resolve faster with IV medication, but the ultimate outcome remains unchanged. A 2015 meta-analysis concluded that the role of high-dose steroids in the acute setting is to speed up recovery rather than affect the long-term prognosis.4 Regarding muscle spasticity and pain, see Table 9.1 for a list of helpful medications.


Transverse myelitis is a poorly understood condition characterized by acute spinal cord dysfunction below the level of a spinal cord lesion. Given its location and chronicity, transverse myelitis can mimic a compressive spinal cord lesion. Although transverse myelitis is thought to be inflammatory, it is unclear whether the trigger is autoimmune, infectious, or paraneoplastic. More likely, it is a heterogeneous syndrome with multiple possible etiologies.5 Diagnosis is usually made with MRI, and treatment is aimed at addressing the underlying inflammation, with corticosteroids being the mainstay of acute management.6


Although stroke in the ED is typically considered in the context of acute presentation, there is an equally concerning chronic component. Brain tissue damaged in a stroke does not heal. Once infarcted, the tissue dies and becomes nonfunctional; even in the absence of revascularization, stroke deficits can improve or completely resolve. The process of overcoming these deficits requires the brain to adjust for the lost function rather than replace it. Neurologic function is transferred to other cells, and this “rewiring” can allow the deficit to improve.

The importance of this rewiring comes in the face of a second, often nonneurologic insult. When faced with another challenge, such as infection or sleep deprivation, the brain can decompensate and allow the stroke deficit to emerge again or worsen. Termed recrudescence, the
recapitulation of old stroke deficits should prompt the clinician to look beyond stroke. Indeed, it is unlikely that the patient has a new infarct that exactly matches the neuroanatomy compensating for the old deficit. It is more likely that another process, such as occult infection, is causing the patient’s brain to re-exhibit the old stroke pattern. Recrudescence must be differentiated from an acute stroke, and treatment should be focused on the acute process rather than anchoring on the neurologic deficit.

In addition to recrudescence, many patients present with complications of stroke-related disability. Weakness can precipitate falls. Swallowing impairment can lead to aspiration. Patients with strokes sometimes present with pain that is thought to be a centrally mediated variant of complex regional pain syndrome (CRPS; see section that follows).7


Emergency clinicians are familiar with the acute management of spinal cord trauma. However, many clinicians are less familiar with the chronic complications of the same injuries. Patients with spinal cord injuries face numerous chronic problems associated with the repercussions of spinal cord injury and paralysis. In the weeks and months following spinal cord injury, blood pressure often drops and orthostasis is common. This is likely a result of muscle atrophy and paralysis. These symptoms usually level off as unused muscles become spastic and systemic circulation adjusts.

Coronary artery disease is an often-underappreciated component of spinal cord injury. It may be 3 times higher in patients with spinal cord injury than in the general population.8 This is likely caused by poor mobility and reduced capacity for aerobic exercise. Accordingly, spinal cord injury should be viewed as an independent risk factor when evaluating a patient with chest pain.

Immobility can become even more pronounced as patients with spinal cord injury become older. Beyond the usual changes associated with aging, such as osteoarthritis, patients with spinal cord injury are far more likely to develop heterotopic bone formation, further limiting joint motion. Some degree of heterotopic ossification is seen in 20% of patients with traumatic brain injury/spinal cord injury.9 It can exacerbate the direct consequences of paralysis and further disable the patient.

Spinal cord injury above the diaphragm can impair ventilation by weakening the chest wall and accessory muscles. This likely contributes to the development of atelectasis and pneumonia. A long-term study that followed patients up to 20 years post injury found that pneumonia was the third most common complication after pressure ulcers and autonomic dysreflexia.10 Spasticity with pain is a frequent complication of spinal cord injury. It is likely the consequence of reduced inhibitory neurostimulation. Although the result is often painful muscle contraction, spasticity also helps increase venous return and maintain blood pressure in a paralyzed patient. Table 9.1 provides a list of medications used to treat spasticity and the acute discomfort it causes.

Most patients with spinal cord injury, even those with incomplete injuries, have some degree of bladder impairment. Lesions that are lower in the cord or cauda equina tend to produce bladder flaccidity, and these patients have trouble with voiding. Higher lesions may result in bladder spasms resulting in ongoing discomfort and difficulties with continence. Sphincter dysfunction can also impair bladder emptying. Patients with spinal cord injury may be unable to sense when their bladders are full, and in rare cases, this can produce a profound vagal reaction and hypotension.

The tools used to treat bladder dysfunction carry their own risks. Many patients with spinal cord injury use catheter devices either intermittently to facilitate continence or as chronic indwelling devices for ease of care. As with any introduction of a foreign body into a sterile space, these devices carry a higher risk of infection. Urosepsis should be high on the differential for a post-spinal cord injury patient presenting with shock.


CRPS is a disorder that is characterized by chronic localized pain out of proportion to, or in the absence of, an inciting event. CRPS is divided into two main categories: CRPS type 1 encompasses cases without an obvious peripheral nerve injury (roughly 85% of cases) and CRPS type 2 is defined as CRPS with a clear mechanism for peripheral injury such as a crush injury or operation (15% of cases).11

The primary manifestation of CRPS is chronic, often extreme pain more commonly found in a patient’s upper extremity. Sensory disturbances in a peripheral nerve distribution may also be present. Roughly two-thirds of CRPS patients have functional motor weakness related to pain. Autonomic symptoms, such as skin color changes, skin temperature changes, or sweat production may also be present. The cause of CRPS is unknown. Historically, theories have focused on nerve injury and the potential for a “short circuit” in nerve conduction. This type of explanation seems less probable, given that many CRPS patients have no inciting injury. More recent research has found elevated levels of inflammatory cytokines in CRPS patients, leading to the hypothesis that local release of pain mediating peptides may be the underlying etiology.12

Although no curative treatment exists for CRPS, rehabilitation and analgesia are the mainstays of management. In the acute setting, a patient may present with pain out of proportion to any physical findings. There is no diagnostic test for CRPS; thus, acute management is focused on ruling out correctable causes, for example, necrotizing fasciitis, compartment syndrome, and acute limb ischemia, all of which can present with extreme pain in a relatively normal-appearing limb. In a patient with known CRPS, management of acute pain should focus on providing analgesia, encouraging motor function, and ensuring follow-up that provides both physical therapy and chronic pain treatment (see evidence section).

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Jun 23, 2022 | Posted by in EMERGENCY MEDICINE | Comments Off on Acute Presentations in Chronic Neurologic Conditions

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