18 Rickets Of Vitamin D Deficiency,Tetany Of Vitamin D Deficiency

Rickets of Vitamin D Deficiency Tetany of Vitamin D Deficiency
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Rickets

& Rickets of Vitamin D Deficiency
Introduction
Physiological function and regulation of VitD
Etiology
Pathology
Pathogenesis
Clinical manifestations
Diagnosis
Differential diagnosis
Prevention
Treatment
& Tetany of VitD Deficiency

Rickets ---failure in mineralization of
growing bone or osteoid tissue (children)
the end of long bone, shaft
Osteomalacia --mature bone (adults)
Rickets of Vitamin D deficiency ---
chronic systemic nutrition-deficient disease
(<2y)

Introduction
Etiology
Pathology
Pathogenesis
Diagnosis
Prevention
Treatment

＊ VitD （ Vitamin D ）
important in mineralization of newly
formed osteoid
＊ PTH （ parathormone ，甲状旁腺素）
＊ CT （ calcitonine, 降钙素）
Factors associated with Ca ,P metabolism and bone development

Physiological function of VitD
＊ antirachitic function facilitation
intestinal absorption of Ca , P(CaBP)
reabsorption of Ca & P in the kidneys
direct effect on mineral metabolism of bone
(deposition and reabsorption)
＊ nonantirachitic function
cell proliferation, differenciation, immunity

Metabolism and regulation of VitD
7-dehydrocholesterol irradiated ergosterol
Provitamin (skin) (plant)
photochemically activation
diet cholecalciferol calciferol
(VitD 3 ) (VitD 2 )
25-hydroxylase in liver
25(OH)D 3
1α-hydroxylase in kidney 24- hydroxylase
1,25-(OH) 2 D 3 24,25-(OH) 2 D 3
active inactive
PTH↑ Ca ↓ , P↓ ( － ) ( ＋ ) Ca ↑ CT↑

Introduction
Etiology
Pathology
Pathogenesis
Diagnosis
Prevention
Treatment

Etiology
＊ Inadequate gain of VitD from mother
＊ Inadequate direct exposure
to ultraviolet rays in sunlight (296-310 nm)
＊ Rapid growth low-birth weight infants
＊ Inadequate intake of VitD
The diets of infants may contain only small amounts of VitD

Predisposing factors to VitD deficiency
disorders interfere with absorption and
utilization of Vit D or Ca or P
celiac disease , steatorrhea, disorders of gastrointestine, biliary duct, pancrea, liver or kidney
drugs administration
* anticonvulsant therapy- (phenytoins, phenobarbital)
interfere with the metabolism of VitD
* Glucocorticoids--antagonistic to VitD in Ca transport

Introduction
Etiology
Pathology
Pathogenesis
Diagnosis
Prevention
Treatment

normal osteogenesis : cartilagenous
intramembraneous
cartilage cells’ normal cycle--( Fig )
zone of resting cartilage
zone of proliferating cartilage
zone of calcifying cartilage
zone of ossication: zone of preparatory
calcification(ZPC, 临时钙化带 )
Pathology

Fig.1 Levels of growth plate zone of resting cartilage zone of proliferating cartilage zone of calcifying cartilage zone of preparatory calcification

In Ricket cartilage cells fail to complete their normal
cycle of proliferation and degeneration;
subsequent failure of capillary penetration
occurs in a patchy manner(Fig)

enlarged costochondral
junction
*Non-calcified, hypertrophied growth plate in rickets (R), compared to a normal growth plate (L).

Pathology
Disturbance of sclerotic calcification
osteomalacia （骨质软化）
osteoid deposition( 骨样组织堆积 )

Introduction
Etiology
Pathology
Pathogenesis
Diagnosis
Prevention
Treatment

Pathogenesis
can be conceptualized to be
the body’s attempt to maintain
normal serum calcium levels

VitD deficiency
↓ Ca, P absorption from the intestine
↓ serum Ca level
parathyroid gland
↓ P reabsorption ↑PTH PTH
in the kidney
↑ mobilization of
Ca ,P from the bone ↓serum Ca
↓ serum P serum Ca->,↓
tetany
↓ Ca,P in ECF
failure in mineralization of osteoid tissue
and cartilaginous matrix
rickets Pathogenesis

Introduction
Etiology
Pathology
Pathogenesis
Diagnosis
Prevention
Treatment

Incidental age 3 m-2 yr
osseous changes in growing bone
relaxation of muscles and ligaments
nonspecific neuropsychatic symptoms
Severe case systemic

Stages
Early stage
Progressing stage
Convalescent stage （恢复期）
Sequelae stage （后遗症期）

Early stage (1)
Symtoms <6(3)m
nonspecific neuropsychiatic---
irritability
restless day and night(unstable sleeping)
increased sweating--particularly around
the head, no relation with weather
bare occiput( 枕秃 )
Signs no obvious osseous change

bare occiput

Early stage (2)
biochemical changes
serum Ca -> or ↓, P ↓,
ALP (Alkaline phosphatase) ↑(500μ/L)
25-(OH)D 3 ↓ , 1,25-(OH) 2 D 3 ↓
Roentgenographic examination
Normal
or ZPC becomes unclear

Progressing stage
＊ symptoms in early stage
＊ osseous changes
＊ retardation of development (movement)

Progressing stage osseous change
＊ Head
craniotabes( 颅骨软化 )(3~6 m)
boxlike appearance ( Caput quadratum) (7~8m)
larger anterior fontanel , delayed closure(2y)
delayed eruption of the temporary teeth,
defects of the enamel and extensive caries,
calcifying permanent teeth’s being affected

boxlike appearance

＊ Chest (about 1yr)
beading of the ribs (rachitic rosary 佝偻病串珠 ) (Fig)
Harrison groove ( 赫氏沟 ) (Fig)
funnel-like chest ( 漏斗胸 ) (Fig)
pigeon breast deformity ( 鸡胸 ) (Fig)

rachitic rosary

Harrison groove Funnel-like chest L: pigeon breast

＊ Extremities
*thickening of the wrists and ankles(Fig )
(Rachitic bracelets 佝偻病手镯、脚镯 )
*bowlegs or knock-knees(Fig)
（ O 型腿、 X 型腿）

R. thickening of the wrists L. thickening of the ankles

Thickening of the wrist Thickening of the ankles

R. bowlegs L. knock-knees

＊ others
spinal column (kyphosis 脊柱后突， s scoliosis 脊柱侧弯 )
concomitant deformity of the pelvis,
ec flat pelvis

kyphosis & scoliosis

Progressing stage
muscle and ligament
poorly developed and lack tone
(late in sitting, standing and walking)
overextension of the great joint

summarized as following table
Histological osteomalacia osteoid
Pathology （骨质软化） deposition
Head Craniotabes Caput
quadratum
chest Harrison groove, funnel Rachitic
-like chest ,Pigeon breast rosary
Spinal Kyphosis, Scoliosis
column
pelvis Flat pelvis
extremities Bowlegs, Knock-knees Rachitic
bracelets

Progressing stage
Biochemical changes
serum Ca↓, P↓,
serum ALP (Alkaline phosphatase)↑↑
serum 25-(OH)D↓ 1,25-(OH) 2 D 3 ↓
urine cyclic AMP↑

Progressing stage
Roentgenographic examination (Fig)
＊ rachitic metaphysis
(deposition of nonrigid tissue)
* at the end of the shaft
(widdened, cupping, fraying)
** ZPC becomes unclear even disappear
＊ rarefied cortical bone (↓density )

Upper limp Normal X rays Rachitic metaphysis

Lower limp Normal X rays Rachitic metaphysis

Convalescent stage
(after adequate antirachitic treatment)
＊ Clinical manifestation improved---
soon regain muscle tone, mentally improved
several days serum Ca, P ↑ ->N
4-6w ALP ↓-> N
＊ roentgenographicly improved----
2-3w - ZPC reappears, bone density↑
4w - ZPC, rachitic metaphysis and shafts
becomes united

Sequelae stage
>2-3 yr
Severe rachitic child leave osseous deformities
— bowleg or knock-knee,
pigeon chest, funnel-like chest,
kyphosis, scoliosis,
head deformity, etc.
Biochemical change and Roentgenographic examination normal

Sequelae stage

Introduction
Etiology
Pathology
Pathogenesis
Diagnosis
Prevention
Treatment

based on
a history of inadequate gain of VitD
Clinical observation
Confirmed by
biochemical test 25 － (OH)D↓(11~60 μ g/ml)
serum Ca↓, P↓,
serum AKP ↑↑
roentgenograghic examination
Diagnosis

Introduction
Etiology
Pathology
Pathogenesis
Diagnosis
Prevention
Treatment

＊ Other rickets
＃ familiar hypophosphatemia ( 家族性低磷血症）
or X-linked hypophosphatemia(XLH)
＃ VitD-dependent rickets
or Ca ++ deficient form of rickets
＃ Renal tubular acidosis
rickets, metabolic acidosis, polyuria, alkaluria
＃ Renal Osteodystrophy
＃ Hepatic diseases associated with rickets

Introduction
Etiology
Pathology
Pathogenesis
Diagnosis
Prevention
Treatment

＊ pregnant and lactating mothers
adequate sunlight; VitD 800U/d;
diet rich in Ca, P, VitD
＊ Infant
exposure to ultraviolet light
daily VitD supplementation
Term infant 400 U/d(2w~2yr)
premature infants 800 U/d(2w~3m),
400 U/d(3m~2yr)
*summer !
Prevention

Introduction
Etiology
Pathology
Pathogenesis
Diagnosis
Prevention
Treatment
&Tetany of VitD Deficiency

To control the progressive stage
prevent osseous deformity
N atural and artificial light
Nutrition
VitD analogue administration
Prevent and treat complication
Treatment

VitD analogue administration
Orally VitD 2,000~4,000 IU/d × 2~4 W
1,25(OH) 2 D 3 0.5 ~ 2 μg/d × 2~4 W
then VitD 400 IU/d (10ug/d)
Single dose im VitD 3 200,000-300,000 IU
2-3m later VitD 400 IU/d
reevaluation q1m
Treatment

Introduction
Chemical Pathology
Prediposing factor
Diagnosis & Differential diagnosis
Treatment

R achitic tetany
Incidental age <6m( 4m-3yr)
Form of plasma Ca
8~10% 40% 45~50% IONIZED active form— PH 、 serum P BOUND protein COMPLEXED

Introduction
Chemical Pathology
Prediposing factor
Treatment

VitD deficiency
↓ Ca, P absorption from the intestine
↓ serum Ca level
parathyroid gland
↓ P reabsorption ↑PTH PTH
in the kidney
↑ mobilization of
Ca ,P from the bone ↓serum Ca
↓ serum P serum Ca->,↓
tetany
↓ Ca,P in ECF
failure in mineralization of osteoid tissue
and cartilaginous matrix
rickets Pathogenesis

serum Ca 2+ <0.75~1mmol/L
serum Ca<1.75~1.88 mmol/L
the loss of the inhibitory control that
Ca exert on the neuromuscular junctions
muscular irritability
Chemical Pathology

Introduction
Chemical Pathology
Prediposing factor
Treatment

Prediposing factor
VitD deficiency
accompany with dull parathyroid response
Relative Ca deficiency
*enough exposure to sunlight (spring, summer)
or VitD administration
*concomitant inadequate Ca absortion
from the intestine
Pathological condition
fever, infection, neonatal asphyxia, high P level diet

Introduction
Chemical Pathology
Prediposing factor
Treatment

tetany and concurrent rickets
Manifest Tetany (serum Ca 2+ <0.75mmol/L
serum Ca<1.75 mmol/L)
latent tetany (serum Ca 2+ <0.75~1mmol/L
serum Ca<1.75~1.88 mmol/L)

Manifest Tetany
Convulsions brief but recurrent,
conscious between seizures
Laryngospasm inspiratory obstruction
high-pitched inspiratory crow apnea
Carpopedal spasm (Fig )

Fig. Carpopedal spasm The wrist are flexed, the finger extended, the thumbs adducted over the palms, the feet extended and adducted.

latent tetany
symptoms are not evident, but can be elicited
by ischemia
or mechanical
or electrical
Chvostek sign, Peroneal sign, Trousseau sign
Clinical manifestations stimulation of motor nerves

Latent tetany
Chvostek sign facial spasm
tapping anterior to external auditory meatus
7th(facial) cranial nerve
Contraction of the orbicularis oris occurs with
a twitch of the upperlip or entire mouth
Peroneal sign pedal spasm
tapping the head of fibula
peroneal nerve
dorsiflexion and abduction of the foot

Latent tetany
Trousseau sign carpospasm
A blood pressure cuff on the arm is inflated
above the systolic blood pressure for 5 min
Ischemia of motor nerves by reducing the blood supply
Carpopadal spasm

Introduction
Chemical Pathology
Prediposing factor
Treatment

bases on
manifest tetany, latent tetany
Biochemical changes
serum Ca 2+ <0.75~1mmol/L
serum Ca<1.75~1.88 mmol/L
The combined presence of rickets
Dagnosis

Afebrile convulsion
H ypoglycemia (Glu ↓ )
Hypom agnesemia (Mg ↓ )
I nfantile spasms
Primary hypoparathyroidism(P ↑ )
Infection of central nervous svstem
acute laryngitis

Prognosis
good unless treatment is delayed,
death rarely occurs
(may result from laryngospasm and cardiac dilation)
Prevention
identical to that of VitD deficient rickets

Introduction
Chemical Pathology
Prediposing factor
Treatment

Anticonvulsive treatment
＊ oxygen inhalation
＊ drugs
10% Chloral hydrate 0.4~0.5 ml/kg
r.e (retention enema)
Valium 0.1-0.3 mg/kg im. iv.
Treatment

＊ Active treatment —
↑ serum Ca ＞ tetany level
Calcium gluconate (10%) 5~10 ml in
GS(10%~25%) 10~20 ml
iv （ >10 min ） cardiac arrest ！
not im or s.c. Local necrosis!
＊ Treatment for rickets
Treatment

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18 Rickets Of Vitamin D Deficiency,Tetany Of Vitamin D Deficiency

by ghalan on Feb 06, 2010

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18 Rickets Of Vitamin D Deficiency,Tetany Of Vitamin D Deficiency — Presentation Transcript