Nigerian Journal of Paediatrics

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

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

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.

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.

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

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

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

192

References

1. Venance SL, Cannon SC,

6. Cao L, Li X, Hong D. Normo-

11. Dandge VP, Pagarkar WB,

Fialho D, Fontaine B, Hanna

kalaemic periodic paralysis

Agarwal M, Dharnidharka

MG, Ptacek LJ, et al. The pri-

with involuntary movements

VR, Rathi SP. Primary hypo-

mary periodic paralyses: Diag-

and generalized epilepsy asso-

kalaemic periodic paralysis.

nosis, pathogenesis and treat-

ciated with two novel mutations

Indian Pediatr 1994; 31: 326-

ment. Brain 2006; 129: 8-17.

in SCN4A gene. Seizure 2015;

2. Francis DG, Rybalchenko V,

24: 134-6.

12. Lascano AM, Korff CM,

Stryk A, Cannon SC. Leaky

7. Platt D, Griggs R. Skeletal

Picard F. Seizures and epilep-

sodium channel from voltage

muscle channelopathies: New

sies due to channelopathies

sensor mutations in periodic

insights into the periodic pa-

and neurotransmitter receptor

paralysis, but not paramyoto-

ralyses and nondystrophic

dysfunction: A parallel be-

nia. Neurology 2011; 76(19):

myotonias. Curr Opin Neurol

tween genetic and immune

1635-41.

2009; 22(5): 524-31.

aspects. Mol Syndromol 2016;

3. Kullmann DM, Waxman SG.

8. Arya SN. Periodic paralysis.

7: 197-209.

Neurological channelopathies:

JIACM 2002; 3(4): 374-82.

13. Sripathi N. Periodic paralyses

New insights into disease

9. June-Bum K, Kyung-Yul L,

[Internet]. 2017 [updated 2017

mechanisms and ion channel

Jaekyn H. A Korean family of

May 18; cited 2017 Aug 14].

function. J Physiol 2010; 588:

hypokalaemic periodic paraly-

Available from: http://

1823-7.

sis with mutation in a voltage-

emedicine.medscape.com/

4. Jurkat-Rott K, Lehmann-Horn

gated calcium channel

article/1171678.

F. State of the art in hereditary

(R1239G). J korean Med Sci

14. Matthews E, Portaro S, Ke Q,

muscle channelopathies. Acta

2005; 20: 162-5.

Sud R, Haworth A, Davis MB,

Myol 2010; 29(2): 343-50 .

10. Rajesh Kumar M, Bharath RV,

et al. Acetazolamide efficacy

5. Lehmann-Horn F, Rudel R,

Rammohan P, Agrawal A.

in hypokalemic periodic pa-

Jurkat-Rott K. Nondystrophic

Clinical profile in hypokalae-

ralysis and the predictiverole

myotonias and periodic paraly-

mic periodic paralysis cases.

of genotype. Neurology 2011;

ses. In: Engel AG, Franzini-

Eur J Gen Med 2014; 11(1): 6-

77: 1960-4.

Armstrong C, editors. Myol-

ogy: 3

ed. New York:

McGraw-Hill; 2004. pp. 1257-

300.