myasthenia gravis ( mg ) is an autoimmune disorder involving development of auto - antibodies against specific proteins in the postsynaptic membrane of the neuromuscular junction , typically against the acetylcholine receptor ( achr ) or related proteins .
it is characterized by weakness , often in the ocular , bulbar , limb , and respiratory muscle groups .
this disorder is often insidious and , as a result , may go undiagnosed for a significant period of time until an acute exacerbation occurs .
while it is well known that the mechanism behind mg is autoimmune , there are several proposed etiologies for guillain - barr syndrome ( gbs ) , which is also known as acute immune - mediated polyneuropathy .
there is significant evidence supporting a possible autoimmune etiology for gbs . if this is in fact true , it is also possible that the two diseases may develop concurrently .
while this is unusual , several recently published studies highlight such cases of concurrent mg and gbs . this co - occurrence could involve certain common proteins , as the two diseases can present somewhat similarly .
a 36-year - old male patient with no significant past medical history presented to the emergency room with symptoms of generalized weakness , dehydration , and distal weakness in both upper and lower extremities for 2 weeks . upon physical examination , the patient was tachycardic and appeared lethargic .
his fingerstick was recorded as 305 mg / dl ( normal values : 7099 mg / dl ) , and his urinalysis was significant for a high urine glucose , large ketones , and trace protein .
the patient was determined to be hyperglycemic , likely due to new - onset diabetes mellitus , and was admitted to the hospital for further management of his symptoms . over the next few days , the patient developed bilateral ptosis and his distal weakness persisted , involving bilateral wrist and foot drop .
1a ) , and he had an expressionless face due to involvement of facial muscles .
the patient 's tachycardia also persisted with his heart rate ranging from 110 to 130 bpm . upon further examination ,
the patient 's weakness progressed , and shortly after , he began to complain of dysphagia and associated weakness upon attempted flexion of his head . upon further questioning ,
the patient remembered experiencing a transient unilateral ptosis 2 weeks before admission , but denied experiencing any other myasthenic symptoms .
based on these findings and the progression of the symptoms , two main diagnoses were considered : mg with acute exacerbation and gbs .
mri of the brain was normal , and nerve conduction studies ( ncss ) showed prolongation of f waves , decrease in compound muscle action potentials , and marked reduction in conduction velocities in bilateral tibial , peroneal , median , and ulnar nerves .
additionally , repetitive nerve stimulation studies of abductor pollicis brevis were performed and resulted in a decremental response ( fig .
, achr antibody levels were found to be significantly elevated ( 55.00 nmol / l , with normal levels being < 0.30
a lumbar puncture was performed and revealed no white blood cells ( normal values : 05 mm ) and a protein level of 95 mg / dl ( normal values : 1545 mg / dl ) suggesting albuminocytologic dissociation .
as the patient 's weakness progressed , he developed respiratory distress and was intubated . at this time , he was transferred from the neurology service to the medicine intensive care unit .
the clinical features of areflexia , albuminocytologic dissociation , and ascending paralysis leading to respiratory failure were all suggestive of gbs
. the miller - fisher variant of gbs was considered at this point due to the patient 's ophthalmoplegia .
based on this , the gq1b ( anti - ganglioside q1b ) antibody test was performed and was found to be negative . after the intubation ,
five cycles of plasmapheresis were completed , after which the patient was started on pyridostigmine .
the patient was successfully weaned from the ventilator , but was later found to have increased secretions due to the pyridostigmine . as a result , he was re - intubated , and pyridostigmine was discontinued . at this time ,
as plasmapheresis is known to only have a transient effect , the patient was also started on 40 mg of prednisone .
since the patient 's glycosylated hemoglobin levels were 14% ( normal values : 3.46.1% ) , his blood glucose levels were optimized with insulin . despite these treatments
, it remained difficult to wean the patient off the respirator , and other factors for the failure to extubate were ruled out . at this point ,
five doses of intravenous immunoglobulins were given , and clinically , the patient began to improve , although his progress was slow .
mycophenolate was started as a steroid - sparing agent , and pyridostigmine was later restarted at low doses .
the patient continued to improve and the deep tendon reflexes returned to normal in lower and upper extremities .
with regard to his new - onset diabetes , the patient was found to have glutamic acid decarboxylase ( gad ) antibodies . eventually , the patient improved enough to be discharged to a specialty hospital for long - term care ( fig .
written informed consent was obtained from the patient for publication of this case report and accompanying images .
mg is an autoimmune disorder which arises due to an antibody - mediated t - cell - dependent attack on the proteins present in the postsynaptic membrane of the neuromuscular junction .
typically , patients who have mg present with a weakness in the ocular , bulbar , limb , and/or respiratory muscles .
some patients may only have ocular symptoms , while others may have more generalized symptoms .
initially , the patient will experience a relapsing- and remitting - type pattern ; but as the disease progresses , the symptoms persist , although they still may fluctuate in severity . in this case , the patient presented with ocular symptoms that are typical for mg  bilateral ptosis and ophthalmoplegia .
our patient also had bilateral facial muscle weakness resulting in a myasthenic sneer , which is a rare clinical feature . on occasion
, patients may present with a dropped head syndrome , as the neck extensor muscles give out , but interestingly , our patient had trouble with flexion , rather than extension of his head .
furthermore , the limb weakness experienced by mg patients is typically proximal , and the arms often appear to be affected more by the disease than the legs .
distal limb weakness ( as seen in our patient ) is less common , but has been noted in about 10% of cases in a few studies involving mg patients .
this case is also notable for the fact that the patient had no known past medical history of symptoms attributable to mg , and he presented with acute exacerbation subsequently involving the respiratory muscle weakness .
weakness involving respiratory muscles is rarely the presenting feature in the first 2 years of onset . on occasion
, the patient will present with respiratory insufficiency that is out of proportion to his limb or bulbar symptoms , as seen with our patient .
this is a serious situation , and these patients should be admitted to the intensive care unit , where vital capacity and negative inspiratory force are the main parameters used to monitor their progress .
additionally , acute exacerbation can be secondary to certain medications ( aminoglycosides , -blockers , and magnesium ) .
as discussed above , we also tested for the presence of gad antibodies in this patient based on his initial presentation with symptoms of new - onset diabetes mellitus .
these antibodies have been classically associated with stiff - person syndrome ; however , their presence simply suggests that the patient 's symptoms are attributable to an autoimmune disease .
gad has been shown to be involved in the synthesis of gaba , and antibodies directed against gad are present in several other autoimmune diseases , including diabetes mellitus and mg . although mg was confirmed in this patient , the presence of ascending paralysis , areflexia , persistent tachycardia , prolonged f waves , demyelinating results of the ncss , and albuminocytological dissociation in cerebrospinal fluid were all suggestive of a possible concurrent diagnosis of gbs .
the ncs indicated an axonal loss and demyelination , which can be seen with gbs and also with polyneuropathy secondary to complications of diabetes mellitus .
gbs is characterized by a progressive and symmetric muscle weakness , accompanied by absent or decreased deep tendon reflexes , as seen with this patient .
typically , the weakness in gbs begins in the legs , although some patients have experienced initial arm and/or facial muscle weakness .
additionally , patients may experience considerable respiratory muscle weakness and may subsequently need to be intubated .
paresthesias , along with back and limb pain , are often experienced especially in the acute stages ; and autonomic dysfunction may be present .
these are , however , non - specific symptoms and can be seen in other diseases , such as diabetes mellitus .
there are several theories regarding the exact etiology behind gbs , but the prevailing one suggests an autoimmune mechanism .
one popular theory is that of molecular mimicry , in which the body responds to certain antigens ( from the infectious agent , vaccine , etc . ) which have a similar composition to host proteins , and an attack is thus launched against the host .
thus , it is often helpful to look at the diagnostic criteria provided by the national institute of neurological disorders and stroke , which are as follows : progressive weakness of more than one limb ( also trunk , bulbar , and facial muscles , and/or external ophthalmoplegia ) and areflexia .
supportive features include progression of symptoms , relative symmetry of symptoms , cranial nerve involvement , autonomic features , elevated protein with cell counts , afebrile , electromyogram and nerve conduction abnormalities consistent with gbs , mild sensory deficits , and lastly a halt in the progression of the disease and a clear recovery .
typically , the results of ncss in gbs are suggestive of demyelination , such as a delay in f waves , decreased nerve motor action potentials , and/or conduction block .
the abnormalities must be seen in at least two nerves , which are rarely affected in other types of neuropathies , to be consistent with gbs . as these criteria are quite broad , some of our patient 's symptoms that do not fit the primary diagnosis of mg can then be considered to be a result of gbs .
for instance , the ocular symptoms are normally more prominent and distal weakness is rarer in mg patients .
for example , in 2008 , lau et al .   described the case of an 84-year - old chinese woman with a co - occurrence of mg and gbs ( miller - fisher variant ) .
the investigators proposed that since the patient 's immune system had already been activated due to the underlying mg , it increased the likelihood that autoantibodies against other antigens could develop in the same set of muscles .
unlike our patient , however , this woman had already been diagnosed with mg for some time prior to her admission . another study published
the following year discussed a similar case and proposed that the concept of molecular mimicry was responsible for the co - occurrence .
, was similar to ours in that the patient had no known history of symptoms that could be attributed to mg .
, published in 2010 , again supports the theory of antibodies , in this case , against heat shock proteins . here , the researchers compared antibody levels in patients with mg , gbs , multiple sclerosis , and healthy controls .
they concluded that the mg patients had higher antibody levels than the patients with ms and the healthy controls .
watkins and thomas   found that while diabetic sensory polyneuropathy is the most common neurological manifestation , other symptoms include acute onset painful neuropathy , which presents with burning pain and hyporeflexia , and autonomic neuropathy , which causes sympathetic denervation .
both therapies have been found to be equally effective ; yet , plasmapheresis is preferred due to a more rapid onset of action .
these treatments have been shown to only be a temporary solution , however , and it is therefore important to also initiate high - dose steroids for long - term treatment in mg patients .
however , long - term immunomodulation treatment has not been shown to be necessary in patients with gbs miller - fisher variant . in summary , this patient had a confirmed diagnosis of mg with additional interesting atypical features or a possible co - occurrence of gbs .
the rarity of this co - occurrence is intriguing , and extensive review of the literature showed only two such cases of mg co - existing with gbs .
this case is a unique and rare occurrence , and additional research needs to be conducted to understand the mechanism behind this co - occurrence .
there is evidence supporting the production of certain antibodies in both mg and gbs , and it would be therefore interesting to take a closer look at the similarities in how these two diseases arise .
 myasthenia gravis ( mg ) is an autoimmune disorder characterized by weakness in specific muscle groups , especially the ocular and bulbar muscles . 
 guillain - barr syndrome ( gbs ) presents with ascending paralysis and areflexia , often secondary to an infection . 
 several theories have been proposed regarding the etiology behind gbs , with many studies pointing to a possible autoimmune cause . if this is in fact true , it is also possible that the two diseases may develop concurrently . 
 while this is unusual , several recently published studies highlight such cases of concurrent mg and gbs 
 . this co - occurrence could involve certain common proteins , as the two diseases can present somewhat similarly . 
 this is an unusual case of a patient with no significant past medical history , presenting with generalized weakness and symptoms of new - onset diabetes , who developed bilateral ptosis , distal weakness , and areflexia while in the hospital , raising the possibility of concurrent mg and gbs . 
 although the diagnosis of mg was confirmed by the positive anticholinesterase antibodies and tensilon test , several features , including sudden onset of ascending paralysis and areflexia , were more common in gbs than mg . 
 it is possible , albeit rare , that these two syndromes could have developed concurrently and that the untreated diabetes mellitus could have contributed to the neurological symptoms . 
 this case is reported because of the rarity of its features , diagnostic and management challenges . 
Introduction
Case Report
Discussion
Disclosure Statement