Position of the Knot in Hanging and Strangulation in Asphyxial Deaths in Medico-Legal Autopsies in Lahore

1. Sadaf Nadar 2. Muhammad Iqbal 3. Khurram Suhail Raja 4. Pervaiz A. Rana
5. Javed Iqbal Khokhar

1. Asstt. Prof. of Forensic Medicine & Toxicology, CMH Lahore Medical College, Lahore, 2. Asstt. Prof. of Forensic Medicine, Wah Medical College, Wah Cantt. 3. Assoc. Prof. of Forensic Medicine, Punjab Medical College, Faisalabad 4. Prof. and Head of Forensic Medicine & Toxicology, CMH Lahore Medical College Lahore
5. Prof. of Forensic Medicine, CMH Lahore Medical College, Lahore.

ABSTRACT

Objective: This study was carried out to find out the position of the knot in all the asphyxial deaths due to hanging and ligature strangulation.

Study Design: Retrospective study.

Place and Duration of Study: This study was carried out at Forensic Medicine Department KEMU, Lahore, during the period from Jan. 2006 to Dec. 2008.

Materials and Method: Out of total 2979 medico-legal autopsies, 220 cases of fatal compression to the neck were selected. The autopsy reports, police documents and hospital records were studied.

Results: Out of total autopsies compressive trauma to the neck was in 220 cases (7.39%). Hanging was the commonest cause 42.27%, ligature strangulation 29.09% and manual throttling 23.64%. The manner of death out of 104 cases of hanging was 68.50% (68 cases) with predominance of males (Male/Female ratio 2.78:1). 3rd decade showed higher incidence in males than the females which were more in 2nd decade. No hanging was seen in the 1st decade. The strangulation was common in 2nd, 3rd and 4th decades of life. Males showed higher incidence than females in hanging in 3rd and 4th decade. Females showed higher incidence in 2nd, 3rd and 4th decades in ligature strangulations than males. In throttling males showed higher incidence in 3rd decade than females in 4th decade. The homicidal deaths were 57.27%, suicidal 30.90% and un-determined were 11.82%. Ligature strangulation and throttling were the methods used in homicidal manner (57.27%) while hanging was used for suicide (30.97%). In hanging the position of the knot was at occiput in 62.50% cases and 23.08% had lateral position. In ligature strangulation 78.13% showed the knot on the front and 21.87% lateral.

Conclusion: In hanging, which is a common method of suicide in our country, the knot was at occiput in 65 cases (62.50%), on right or left lateral in 24 cases (23.08%) and in none of the case was on the front. While in ligature strangulation, in 50 cases (78.13%) it was on the front, in 14 cases (21.87%) on right or left side and in none of the case it was on the front.

Key Words: Asphyxia, Hanging, Ligature Strangulation


INTRODUCTION

Neck transmits important vital structures from head to body, like major blood vessels, nerves, wind pipe and esophagus. So this region is most vulnerable to injuries and most important of these injuries is mechanical compression to the neck. This causes mechanical asphyxia and most common means used to do this is by ligature or manual compression. In hanging the body weight acts as a constricting force1. This mechanical compression can also be achieved by direct blow on neck, arms lock, accidental falls on to the neck and accidental entanglement in cords2.

As a consequence of mechanical compression the asphyxia will develop. The outcome will depend upon the effects of the structures involved, individually or in total and method & force applied. Occlusion of the jugular veins will occur with only2 kg of weight; and it will cause obstruction to return of blood to the heart and will appear as cyanosis, congestion and petechiae. Carotids arteries needs 3.5 kg and will cause cerebral ischemia. Pressure on carotid bodies will cause stimulation of baro-receptors in the carotid sinus lying in the internal carotid arteries, and will cause sudden cardiac arrest by stimulation of vagus nerve. The obstruction to the respiratory passages can be achieved with elevation of larynx and pushing the base of tongue against the posterior pharyngeal wall. Due to rigid structures of wind pipe it is difficult to occlude the airways, but 15 kg of tension can do that. Direct pressure on the larynx can also cause the fractures of hyoid and thyroid cartilages.(2, 3, 4, 5,6)

Whatever mechanism is used to achieve mechanical asphyxia, the reduction in O2 level will result in tissue anoxia leading to endothelial damage, capillary dilatation, increased permeability and stasis of blood. This will appear as cyanosis, congestion, petechial haemorhage oedema and serous effusion. This reduction in circulating blood volume will set in a viscous cycle of more anoxia and so on.

MATERIALS AND METHODS

All the medico- legal autopsies which had been conducted in the Department of Forensic Medicine & Toxicology KEMU Lahore during Jan-2006 to Dec-2008 were studied. The autopsy reports, police documents and hospital records were scrutinized. The asphyxial death cases were studied and analyzed for age, sex, type of compression, manner of death, level in relation to thyroid cartilage, number of turns, fracture of hyoid bone and position of the knot. All those cases where the cause of death was hanging or ligature strangulation were included while other cases were excluded in which the trauma to the neck was present but the cause of death was other than hanging or strangulation.

RESULTS

Out of total 2979 medico-legal autopsies carried out during the three years study period of 2006-2008 in the Department of Forensic Medicine & Toxicology, 220 (7.38%) cases were due to compression of neck. (Table No. 1).

Table No. 1 Causative Agent (2979 cases)

 

Total

%age

Blunt Means

403

13.52

Sharp Means

256

8.5

Fire-arms

1285

43.13

Poisoning

74

2.48

Burns

50

1.68

All Asphyxial Deaths

220

7.38

Electrocution

19

0.64

Drowning

17

0.57

Bomb Blast

65

2.18

Natural

347

11.65

Un-Determined

213

7.15

Total

2979

100.00

Types of Neck Compression:

Three types of neck compression means were seen commonly in our study, out of these 220 cases of asphyxial deaths, the cases of hanging were 104 (47.27%) and 64 cases (29.09%) were those of ligature strangulation. (Table No. 2) (Graph 1).

Table No.2: Types of Neck Compression (220 cases)

Types

No. of Cases

%age

Hanging

104

47.27

Ligature Strangulation

64

29.09

Throttling

52

23.64

Total

220

100.00

 

 

Age and Sex Distribution: The most common age group involved was between 21-30 years (35.91%) and next to it was between 31-40 years (25.91%). Next involved age group was between 11-20 years (17.27%). Total of 144 (65.45%) male cases were seen out of all 220 asphyxial deaths, and females were 76 (34.55%). (Table No. 3).

Table No. 3: Age and Sex Distribution in 220 cases

Years

Male

Female

Total

%age

< 1

-

-

-

-

1-10

2

3

5

2.27

11-20

23

15

38

17.27

21-30

59

20

79

35.91

31-40

36

21

57

25.91

41-50

9

6

15

6.82

51-60

10

7

17

7.73

>60

5

4

9

4.09

Total

144    (65.45%)

76    (34.55%)

220

100.00

Manner of Death: Manner of death is either natural or un-natural. Un-natural in our study include homicide, suicide or un-determinable death in which the exact cause of death could not be ascertained due to natural or acquired limitations. No case of accidental asphyxial death was reported during the period of study.

The distribution according to manner of death showed that, incidence of homicide was 57.27% (126), suicidal 30.90% (68), while 11.82% (26) cases remained un-determined. Male to female ratio was 2.15:1 in homicidal deaths, 2.77:1 in suicidal and 1.6:1 in un-determined deaths. (Table No. 4)

Position of Knot: The knot was present on occipital position in 65 cases (62.50%) and it was on lateral right or left positions in 24 cases (23.08%) and in ligature strangulation in 50 cases (78.13%) the knot was on front and in 14 cases (21.87%) it was on lateral right or left . (Table No. 5).

 


 

 

Table No. 4: Manner of Death in All Asphyxial Deaths (n=220)

Age

(Years)

Total

          Homicide

    M/F Ratio 2.15:1

            Suicide

     M/F Ratio 2.77:1

      Un-Determined

      M/F Ratio 1.6:1

M

F

Total

M

F

Total

M

F

Total

<1

0

0

0

0

0

0

0

0

0

0

1-10

5

2

3

5

0

0

0

0

0

0

11-20

38

8

6

14

5

9

14

7

3

10

21-30

79

36

11

47

20

06

26

4

2

6

31-40

57

20

14

34

16

02

18

3

2

5

41-50

15

8

2

10

4

01

5

0

0

0

51-60

17

6

3

9

5

0

5

0

3

3

>60

9

6

01

7

0

0

0

2

0

2

Total

220

86

40

126

(57.27%)

50

18

68

(30.91%)

16

10

26

(11.82%)

 


Table No. 5: Position of knot in hanging

 

 

Position of knot

 

Hanging

Front

-

-

Occiput

       65

   62.50%

Lateral (right or left)

       24

   23.08%

Ligature Strangulation

Front

       50

   (78.13%)

Occiput

-

-

Lateral (right or Left)

       14

   (21.87%)

DISCUSSION

Incidence of Death: Our study showed that, fatal compression to the neck caused 220 deaths out of 2979 medico-legal autopsies carried out at the Department of Forensic Medicine & Toxicology K.E.M.U. Lahore with an incidence of 7.39% and 89.43% of all asphyxial deaths. This incidence is much higher than reported by 1.6%7, 1.75%8, and 1.88%9 of all asphyxial deaths. And it was 2.94%10 of all deaths 24.53% of all asphyxial deaths, 5%11 of all deaths and 82% of asphyxial deaths, and 1.17%12& 12.4%13 of all and 5.5% of all deaths but lower than 15.7%14 in Edirne Turkey.

Type of Neck Compression: The incidence of hanging is the highest 47.27% (n=104), next is ligature strangulation 20.09% (n=64) and throttling is 23.64% (n=52). These values are comparable with (hanging 57%, strangulation 21%, and throttling 18%) 9, (hanging 61.17%, ligature strangulation 21.19% and throttling 17.64%) 8, (hanging/ligature strangulation 80.7% and throttling 19.3%) 7, (hanging/ligature strangulation 85% and throttling 6%) 15, (ligature strangulation 12.4%) 13, (ligature strangulation 19.23%, throttling 46.15%) 10, (hanging 41.8%, ligature strangulation 2.9% and throttling 2.3%) 14, (hanging 69%) 11.

Age and Sex Distribution: The highest incidence of all neck compression deaths, hanging, ligature strangulation and throttling is seen in the 21-30 years of age group. This is comparable with the previous studies also 57% 11, 3rd decade 12, average of 41.9 years 14. Bowen16 has shown highest incidence of hanging in 50-59 years of age. Guarner & Hanzlick17 mentioned 31 years of age showing highest incidence in USA.

Male/Female Ratio: In our study male/female ratio in hanging is 2.25:1, ligature strangulation 2.05:1 and in throttling 1.26:1. So males have shown higher incidence in all the three asphyxial deaths.

In hanging males were 69.23%, which is higher than females having 30.76%. This is comparable with those of 83.9% males of Azmak14, 2.7:1 (males 73.07% and females 26.92%) of Bashir MZ9 et al.In ligature strangulation and throttling Bashir MZ9 has shown 58.9% males and 41.02% females. Azmak D14 has quoted 1:3 for strangulation and 1:2 for throttling, and Srivastava AK10 had shown 30.77% males and 69.23% females, giving higher incidence in females than males.

Manner of Death: The homicidal deaths in our study were which shows higher incidence than that of Bashir MZ9 45.05% but lower than that of Demirci S13 85%.

Suicidal 30.90% in our study is lower than Bashir MZ9 45.45% and Azmak D14 47%. It is higher than that of Demirci S13 15%.In hanging the suicidal incidence in our study was 65.38%, which is lower than that of Bashir MZ9 86.53%. Homicidal showed 9.62% which is also higher than 3.84%9. But lower than that of Bowen DA16, which is 95%.There was no case of accidental hanging; however Bowen DA16 reported 5% of auto-erotic accidental asphyxial deaths.

Position of Knot: In 65 cases (62.50%), the knot was present at occiput, which is comparable with the findings of Azmak D12 narrating 66% on occiput in hanging and 88.7% on the chin in ligature strangulation. In 24 cases (23.08%), it was on lateral side, either right or left. Whereas in ligature strangulation, in 50 cases (78.13%) the knot was on front and in 14 cases (21.87%) it was on lateral right or left. Our findings are also comparable with those of Bawon DA.16 et al and Sharma BR15 et al.

CONCLUSION

Hanging remains the most preferable method of suicidal asphyxial deaths and ligature strangulation being the next in number in homicidal asphyxial deaths. In hanging, the position of the knot is typically at the occiput in most of the cases, and similarly in homicidal strangulation the knot is on the front in majority of the cases.

REFERENCES

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2.       Knight B. Forensic Pathology. 2nd ed. Amold: London;1996.p.90.

3.       Shepherd R. Simpson Forensic Medicine. 12th ed. Arnold:London;2003.p.97.

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8.       Malik SA, Aziz K, Malik AR, Rana PA. Fracture of Hyoid Bone: An indicator of death in strangulation. Pak Postgraduate J 1999;10(4):
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9.       Bashir MZ, Malik AR, Malik SA, Rana PA, Aziz K, Chaudhry MK. Pattern of Fatal Compression of the Neck. A five Year study in Lahore. Annals 2000; 6(4):396-98.

10.    Srivastava AK, Gupta SMD, Tripathi CB. A study of Fatal Strangulation Cases in Varanasi (India). The Am J of Forensic Med & Pathol 1987; 8(3): 220-24.

11.    Hussain SM, Mughal MI, Din SZ, Baluch NA, Bukhari SMZ, Malik S. et al. An autopsy study of Asphyxial Deaths. Med. Forum 2008;19(4):27-30.

12.    Verma SK, Lal S. Strangulation deaths during 1993-2002 in East Delhi (India). Leg Med Tokyo 2006;8(4):1-4.

13.    Demirci S, Dogan KH, Erkol Z, Gunaydin G. Ligature Strangulation Deaths in The Province of Konya (Turkey). J Forensic Leg Med 2009; 16(5):248-52.

14.    Azmak D. Asphyxial Deaths. A Retrospective Study and Review of the Literature. Am J of Forensic Med and Pathol 2006; 27(2): 134-144.

15.    Sharma BR, Harish D, Sharma A, Sharma S, Singh H. Injuries to The Neck Structures in Death due to Constriction of Neck, with a special reference to Hanging. J Forensic Leg Med 2008;15(5):298-305.

16.    Bawon DA. Hanging-A review. Forensic Sci Intl 1982; 20:247-49.

17.    Demirci S, Hanzlick R. Suicide by Hanging. The Am J of Forensic Med and Pathol1987;8(1):23-26.

 

 

Address for Corresponding Author:

Dr. Sadaf Nadar,

 

Assistant Professor Forensic Medicine,
Department of Forensic Medicine & Toxicology,
CMH Lahore Medical College, Lahore.