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Nigerian J Paediatrics 2017 vol 44 issue 1

Nigerian J Paediatrics 2017 vol 44 issue 1

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Periodic paralysis with generalized epilepsy in a Nigerian child A case report
Niger J Paediatr 2017; 44 (4): 190 192
CASE REPORT
Imoudu IA
CC BY
Periodic paralysis with
generalized epilepsy in a
Nigerian child: A case report
DOI:http://dx.doi.org/10.4314/njp.v44i4.4
Accepted: 15th August 2017
Abstract : The periodic paralyses
tion, the index episode had been on
are a rare group of muscle channel
-going for 2 days.
Imoudu IA (
)
opathies characterized by inter-
Management of the acute paralytic
Department of Paediatrics,
mittent attacks of episodic muscle
episode and prophylaxis were ac-
Federal Medical Centre, Azare,
weakness of variable duration.
complished with oral acetazola-
Bauchi state
Typically, symptoms begin in the
mide administration. This report
Email: tomhe164@yahoo.com
first or second decade of life. This
underscores the ease with which
case describes a 13 year-old girl
effective prevention of paralytic
with generalized epilepsy who
episodes in periodic paralyses
presented with a 9- year history of
could be achieved in a resource-
recurrent attacks of inability to
poor setting.
walk. Attacks which occurred at a
frequency of 2-3 times a year with
Keywords:
Periodic paralyses,
spontaneous resolution were often
Channelopathies, Epilepsy, Aceta-
triggered by exposure to cold,
zolamide, Nigerian, Child.
strenuous exercise and occasion-
ally by convulsions. At presenta-
Introduction
that may accompany early diagnosis and appropriate
treatment.
The periodic paralyses (PP) are a rare diverse group of
muscle channelopathies characterized by intermittent
Case report
attacks of muscle weakness due to anomalous sarcole-
mal excitability. They encompass a group of diseases
1
A 13 year-old Fulani girl presented with a 9-year history
ensuing from mutations in the SCN4A, CACNA1S and
of recurrent episodic attacks of inability to walk. The
KCNJ2 genes.
1-6
attacks were characterized by sudden onset inability to
As a rule, the majority of patients experience episodic
move the lower limbs, occasionally starting from one
muscle weakness lasting from minutes to days with
limb and eventually involving the other within a few
spontaneous and total recovery. Typically, onset of
1,4
minutes. Attacks usually began early in the mornings,
symptoms is in the first or second decade of life with
triggered by cold (severity and frequency were increased
some patients exhibiting significant improvement in
during the cold harmattan season), rest after strenuous
their 40s or 50s. Symptoms are often precipitated by
5
exercise and occasionally by convulsions. The attacks
exercise, rest following physical activity, cold, mental
occurred at a frequency of 2-3 times a year, usually last-
stress, hormones, or a heavy carbohydrate meal and
ing about 4-12 hours but on rare occasions may reach
some medications. They are also known to be associated
durations of up to 1 week following which spontaneous
with cardiac arrhythmias, essential tremor, and epilepsy.
resolution ensues. The index episode commenced the
6,7
morning after she was flogged by the mother and had
persisted for 2 days at the time of presentation. There
PP are frequently thought to be benign conditions. Nev-
was no family history of similar paralysis or any other
ertheless, life-threatening weakness episodes or progres-
neurologic disorder.
sive permanent weakness have been known to occur.
Furthermore, the attacks create disability, disruption of
She was diagnosed with abdominal epilepsy at the age
school activities and in some instances lead to persistent
of 4 years (the electroencephalogram [EEG] showed
weakness with attendant low self-esteem.
1
focal slowing and epileptiform discharges). However,
The uncommonness of these diseases is underscored by
following a 3-year period of being seizure-free on car-
the paucity of reports among African children (Nigeria
bamazepine, she was gradually weaned-off anticonvul-
inclusive). This report emphasizes the diagnostic chal-
sants over a 6-month period. Seizures recurred 2 years
lenges encountered in our environment, and the need to
later albeit generalized tonic-clonic (EEG indicated gen-
recognize the existence of periodic paralyses amongst
eralized epileptic discharges). At the time of presenta-
Nigerian children. It also highlights the good outcome
tion, she had been seizure-free for 9 months on leveti
191
racetam and sodium valproate.
onset of paralytic episodes and the drop in serum K lev-
Physical examination revealed a fully conscious girl,
els during attacks is suggestive of hypokalaemic PP.
who was well oriented in time, place, and person. There
Intra-ictal normokalaemia in PP has been described, this
was no cranial nerve palsy. She had hypotonia, hypore-
is consistent with the findings in this patient and is in-
dicative of a primary PP.
6,7,11
flexia with muscle power (in all muscle groups) of grade
The absence of a positive
1/5 in both lower limbs. Tone, muscle power, and deep
family history in the index case may be due to the fact
tendon reflexes were normal in the upper limbs. Sensory
that PP are genetically heterogeneous with inconsistent
penetrance.
11,12
examination, skull and spine were normal. Respiratory
Diagnosis of PP is based on clinical fea-
and cardiovascular systems as well as the abdomen were
tures, elevated intra-ictal serum CPK, neurophysiologic
studies and genetic studies.
1,6-8
also normal.
Other investigations that
may be useful are, nerve conduction studies, needle
The serum potassium (K) at the time of muscle weak-
electromyography and long exercise testing (McManis
test).
6-10
ness was 4.8 mmol/L (between attacks K= 5.3 mmol/L),
EEG showed generalized epileptic discharges, Electro-
cardiogram (ECG) and Brain Magnetic Resonance Im-
The differential diagnoses include Myasthenia gravis
aging (MRI) showed no abnormalities. Thyroid hor-
(MG), Sleep attacks (SA), Transient ischaemic attack
mone levels were also normal. Serum creatine kinase
(TIA) and Todd palsy (TP). MG is usually subacute in
(CPK), urineK/creatinine ratio, electromyogram (EMG),
onset and exhibits presence of distinct antibodies. SA
muscle biopsy for histology and genetic studies could
occur at the onset or end of sleep and lasts only minutes,
not be done owing to unavailability of facilities.
TP is a transient focal weakness that only follows a sei-
zure, and TIA usually presents with hemiparesis and
may have sensory symptoms.
13
A diagnosis of periodic paralysis with generalized epi-
Akin to several other reports,
4,6,7
lepsy was made. She was commenced on acetazolamide
this case is associated
at 250mg BD and maintained on the anticonvulsants.
with generalized epilepsy. The reason for this is un-
Two days later she was able to walk without support and
known. However, there has been mounting evidence in
was sustained on acetazolamide for prophylaxis. After
recent years that ion-channel dysfunction is involved in
the molecular basis of various forms of epilepsy.
6,7,12
18 months of follow-up on acetazolamide and leveti-
racetam, she has been free of paralytic attacks and sei-
Treatment of acute episodes and prophylaxis may be
zures.
accomplished with oral acetazolamide; as was done in
this case. Though in use for the prevention and treatment
of paralytic episodes in PP for nearly 50years, the
mechanism of action of acetazolamide in this regard is
largely unknown. Other agents that are effective for
14
Discussion
prophylaxis in primary PP are dichlorphenamide and
spironolactone.
7,8
The PP are usually classified into two groups: primary
or familial PP and secondary PP. The former are auto-
somal dominant disorders resulting from mutations in
the skeletal muscle sodium channel (SCN4A), calcium
channel (CACNA1S) or potassium channel (KCNJ2)
Conclusion
genes. The secondary group have known causes; thy-
7,8
rotoxicosis, chronic renal failure and drugs (angiotensin
In addition to emphasizing the paucity of data on this
converting enzyme inhibitors, angiotensin-II- receptor
group of diseases, this report draws attention to the rela-
blockers and diuretics). The primary type is further
8
tive ease with which acute paralytic episodes can be
classified into hyperkalaemic PP, hypokalaemic PP and
prevented.
Andersen- Tawil syndrome based on serum potassium
(K), response to K administration or presence of associ-
ated anomalies. The primary PP have a common final
1,7
Conflict of interest: None
pathogenetic pathway: anomalous depolarization, which
Funding: None
inactivates sodium channels and renders the muscle fibre
electrically unexcitable.
1-6
Hypokalaemic PP, the com-
monest of all forms of PP is commoner in males and has
a prevalence of 1 per 100,000 population, prevalence of
the others is unknown.
9,10
Although extremely rare, these
Acknowledgement
diseases affect all races.
1,4,8-10
Nevertheless, there is a
dearth of reports of PP among African children. This
The author acknowledges the contribution of the follow-
case is perhaps the first reported in a Nigerian child.
ing to the management of the child; Drs Ahmad H,
Typical of resource-poor settings, diagnosis in this case
Yusuf MO, Umara T, and Makarfi HU.
was based mainly on clinical features. The delay in
11
192
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