Saturday, April 2, 2011

Central Nervous System Involvement and Lupus

Lupus is the great mimicker. It can manifest itself in so many ways that many doctor's do not catch it for years. They suspected lupus in me two years into my diagnosis of Rheumatoid Arthritis because of occasional episodes of pericarditis, pleuritis and glomeruonephritis...and a pesky magenta rash that would come and go. I would get horrible eye pain and no one seemed to connect it to the lupus until 9 years ago. I was always told it was an eye migraine. Because I couldn't tell I was losing peripheral vision, it wasn't an issue until then. That is when my central nervous system was first being recognized as being attacked. Now, I have peripheral neuropathy, in my legs and feet, my arms and hands...and now in my esophagus.

When the central nervous system gets involved, it is usually a sign that you have an aggressive and progressive form of lupus. Among the neurologic manifestations of lupus, the most common are the organic encephalopathies (35-75% of case series), which basically comprise all potential variations of acute confusion, lethargy, or coma; chronic dementias; depression, mania, or other affective disturbances; or psychosis.  I have presented with depression and psychosis.

Acute or subacute mental status changes may be secondary to diffuse cerebritis but should be differentiated from focal cortical dysfunction resulting from thromboembolic cerebrovascular accident (CVA) or from diffuse changes resulting from electrolyte or metabolic derangements (accentuated by concomitant renal failure); medication effects including steroid psychosis (most problematic with high dosages and long durations); aseptic meningitis (seen especially with nonsteroidal anti-inflammatory drugs [NSAIDs]); or opportunistic infections that result in meningitis, encephalitis, brain abscess, or systemic infection with a secondary toxic encephalopathy.

Seizures are already known to occur in 14-25% of patients with lupus compared with 0.5-1% in the general population. Seizures may result from cerebral vasculitis (ischemic or hemorrhagic manifestations) -- this is the type of seizure that I have experienced, cardiac embolism, opportunistic infection, drug intoxication, or associated metabolic derangements. A seizure focus may result from an acute insult or from the development of a seizure focus in an area of prior brain insult. Partial or secondarily generalized seizures are most common, but all seizure types have been reported.

Electrolyte disturbance and medication effects should be excluded, especially those resulting from antidepressants, stimulant medications used to treat fatigue, or withdrawal from sedatives or alcohol. Opportunistic infections should be considered in patients receiving immunosuppressive therapy. Steroid therapy, especially high-dose pulse therapy, has been associated with status epilepticus.

Cranial nerve involvement is also relatively uncommon and usually transient, occurring in roughly 10% of lupus patients. Oculomotor nerve palsies and all other cranial neuropathies have been reported. Visual disturbances tend to be bilateral (80%) and usually occur late in the disease course (77%),

These disturbances include: optic neuritis, retinopathy, and concurrent migrainous features. Anterior segment findings include: keratoconjunctivitis sicca, keratitis, and scleritis. Retinopathy can be associated with cotton wool exudates (indicative of local retinal ischemia) and hemorrhages. There is a reported case of SLE with recurrent laryngeal palsy resulting in vocal cord paresis. Laryngeal electromyography (LEMG) on both cricothyroid and thyroarytenoid muscles confirmed a left recurrent laryngeal neuropathy with ongoing processes of denervation and reinnervation.  I have recurring optic neuritis from vasculitic lesions along with the keratoconjuctivitis sicca (dry eyes) and scleritis (where the whites of the eyes get all RED and demon eye looking).

Peripheral neuropathy occurs in as many as 18% of patients. A sensory or sensorimotor predominantly distal polyneuropathy is most common; however, the patchy deficits and subacute time course of mononeuritis multiplex and the rapidly progressive course of acute demyelinating polyneuropathy have been reported. The neuromuscular junction may be affected, mimicking the weakness patterns (and physiology) of myasthenia gravis or myasthenic syndrome (ELS). Myositis is clinically apparent as proximal weakness and myalgias in 3-5% of patients but, if assiduously sought, may be found in as many as 50%.  In the past 6 months, I have started presenting with swallowing issues very similar to those seen in myasthenia gravis patients.  It is also important to note that my mother has myasthenia gravis, rheumatoid arthritis and ocular citatrical pemphigoid -- a rare autoimmune condition of the eye.  Yes...my family seems to be prolific with the weird diseases.

Autoimmune-mediated myopathy must be differentiated from myopathy induced by steroid or antimalarial therapy as well as arthralgias and other musculoskeletal sequelae of SLE. Distinction from arthralgias and other musculoskeletal conditions is based on symmetrical, proximal muscle weakness (in excess of that weakness explained by painful give way), elevated creatine kinase, and absence of other musculoskeletal findings. Distinguishing SLE-induced myopathy from medication-induced myopathy is dependent on the time course of the weakness in relation to changes in medical therapy. In difficult cases, clinical response to increasing or decreasing the suspected medication may settle the issue.  The testing is ugly, painful and generally not something to want to go through more than once.

Chronic fatigue is a common symptom in SLE and usually does not relate to objective muscular effort, ie, walking up stairs may seem no harder than walking on level ground. Fatigue may contribute to both self-perceived and to measurable cognitive impairment, chiefly by impairing frontal lobe attentional functions. This may relate to metabolic dysfunction of brain parenchyma, as discussed in Organic encephalopathies. Depression, myopathy, excessive daytime fatigue due to nocturnal sleep disorder, and systemic conditions (i.e., electrolyte disturbance, fluid overload, pulmonary insufficiency) remain in the differential diagnosis. Many patients with mild orthostatic hypotension present with symptoms resembling chronic fatigue and may not complain of the usual presyncopal symptoms.

Cranial neuropathies most commonly result from lupus vasculitis affecting the vasa nervorum supplying the involved nerve. Although optic neuritis (painful or painless subacute loss of visual acuity, usually accompanied by visible inflammation of the optic nerve head) and retrobulbar neuritis are most common, any cranial nerve may be affected. Imaging studies can exclude compressive lesions that result from opportunistic infection, tumor, or aneurysm.

Mononeuritis multiplex results in patchy, asymmetric weakness, sensory loss, or both in the distribution of multiple peripheral nerves or roots. Clinical distinction between proximal myopathy and polyradiculopathy or proximal mononeuritis multiplex may be difficult, requiring electromyogram (EMG) or nerve conduction velocity (NCV) studies or even nerve and muscle biopsies for an accurate diagnosis.

I know its a lot of technical information to absorb.  It was a lot for me to digest  when I first started researching lupus.  I have a good chunk of these issues.  I have had to adjust and change the focus of my life to accommodate my disease and the limitations it has placed on me.  But please do not think that I am not LIVING.  I make the most of my days.  Love those important to me.  I have learned to value the precious moments we create for each other.  If I can help someone who isn't sick, learn the value of creating priceless moments with those they love...then I have accomplished something great.





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